Am I the problem?

23F, 21M — I ended a 4-month situationship over his behavior with other women, but now I miss him terribly. Should I reach back out?
I’m 23F and he’s 21M. We met on a dating app about 6 months ago. We initially messaged a few times, but I wasn’t really interested, so I stopped responding. He eventually found me on Instagram and messaged me there, saying he hadn’t been able to let me go.
I hadn’t dated anyone in about three years. I have a lot of past relationship trauma from an ex and also things I’m still working through from growing up in an abusive relationship between my parents. I think the idea of being with someone who actually had potential scared me. He checked a lot of my boxes, and I think that made me more afraid rather than more interested.
Eventually, I decided to give it a chance.
And our first date was honestly incredible.
It was the kind of date people describe when a best man gives a wedding speech. We stayed up until 3 AM just talking. No phones, no music, no movie, nothing. We just talked about the most random things and laughed the entire night. I remember thinking that I had finally found someone who really got me and made the world feel a little lighter.
He was a perfect gentleman that night. There were a few little things he said he wanted to do that never really materialized later on — things like bringing me flowers or opening the car door — but the actual date itself was amazing.
We also didn’t sleep together that night because he told me he didn’t like doing that on a first date.
Our second date was his company’s gala. I met his coworkers and his longtime childhood best friend, and we had an amazing time. Unfortunately, I drank way too much, blacked out on the way home, and threw up in the Uber. Definitely not my finest moment.
But he didn’t seem turned off at all.
He stayed with me the entire night, took care of me, and even stayed the next day. We slept together, ordered food, and he took me out for coffee. He was incredibly sweet about the whole thing.
After that, we started seeing each other roughly once a week for the next four months.
Most of our time together looked like this: he would come to my place, we would sleep together, order food, talk, cuddle, and he would stay overnight.
And honestly, I loved being around him.
He was incredibly affectionate. He would put his hand on my back, play with my hair, kiss my forehead, call me beautiful, and constantly say kind and positive things to me. I can get very inside my own head and become negative, and his optimism often made me feel better.
There was a softness to him that I really loved.
The problem was that outside of our time together, there wasn't much.
We didn't really text or call throughout the day. He wasn't particularly proactive about planning dates. Most of our relationship existed in these little pockets of time when he would come over once a week.
For a while, I was okay with that because when we were together, things felt really good.
Then, over the last month, I started noticing something that really bothered me.
He follows new women on Instagram constantly. It seems like almost every day there is a new girl. He keeps his following number relatively stable, so he'll unfollow some random account and then follow a new woman.
I also started noticing him liking revealing photos — bikinis, skin-tight dresses, girls posing on boats, etc. Sometimes he'd like the photos and then unlike them a few hours later.
I know Instagram isn't proof of anything by itself, and maybe I'm reading too much into some of it. But because Instagram was literally how he initially pursued me, I don't view following and interacting with women there as completely meaningless.
The final straw was when he went out of town with his friends.
While he was there, he followed a girl who happened to be in the same town that same weekend. He liked a bikini picture of hers and then went back and liked three of her older posts.
That made me think they had potentially interacted in person.
When he came home, he came over to my house. It was actually the day I had to attend a funeral for someone important in my life.
We were sitting on my couch talking when I saw that the same girl texted him on iMessage.
Not Instagram. iMessage.
So, obviously, my mind immediately went to: How did they exchange numbers?
I told him I had seen the text. He didn't really offer an explanation. We were both a little tipsy at that point, but eventually we went to bed and I told him that I found it disrespectful that he was texting other women while he was literally at my house.
He apologized, and we had a conversation about what was going on.
That's when he told me that he was talking to multiple people.
He also told me that he wanted a relationship with me.
That confused me.
I told him I didn't understand how he could say he wanted a relationship with me while simultaneously pursuing other women. I also told him that, from my perspective, his actions didn't really look like someone who was working toward a long-term relationship with me.
He wasn't taking me on many dates. We weren't communicating much outside of seeing each other. He was constantly following new women and interacting with their posts.
We left the conversation there.
Afterward, I had a therapy session, and my therapist encouraged me to be vulnerable instead of reacting from fear or anger.
So I sent him a long message essentially saying:
I like you. I want a relationship with you too. But I can't continue investing my time and emotions into someone who is actively talking to multiple other people. That's a boundary for me. I'm not asking you to do something you're not ready for, but I need to be honest about what I can and can't accept.
He responded that he understood and said he would try to make his actions more aligned with someone who was looking for something long-term with me.
I thought we had gotten somewhere.
Then literally the next day, I noticed he followed another new girl and liked three posts from women that were all pretty revealing/attention-seeking.
He later unliked the posts within an hour.
To me, this completely contradicted the conversation we'd just had.
I felt humiliated and angry, especially because I had just been vulnerable with him and explicitly explained that his behavior with other women was making me uncomfortable.
So I sent him a really rude text.
I'll admit I was drunk when I sent it.
I basically told him that his need for attention from other women was pathetic, that he'd been playing me for months, and that he was lying to himself if he thought he wanted a long-term relationship with me when what he really wanted was attention from multiple women.
I told him he could come get his things.
His response was basically, "Are you serious?" He said that he absolutely did want a long-term relationship with me, but that we had never actually established a relationship or explicitly defined boundaries, so he didn't know what the expectations were.
He also said he wanted to talk about everything in person and that he respected my decision if I still wanted him to get his things.
I didn't engage.
I sent him a picture of his things packed in a bag downstairs and told him they were ready for him.
And I haven't heard from him since.
Now here's where I'm struggling.
I miss him.
A lot.
I think about texting him every single day. I miss talking to him. I miss having him in my life. I miss the way he made me feel. I miss his affection, his optimism, his stupid jokes, sleeping next to him, getting food together, and honestly just having him around.
And I want to be clear that missing him doesn't mean I think the things that hurt me didn't happen.
I still don't like the way he was behaving with other women. I still don't think my boundaries were unreasonable. And I don't want to become the woman who accepts behavior that makes her feel insecure and disrespected just because she's afraid of losing someone.
But I also wonder if I handled this badly.
Maybe I went from trying to communicate my feelings to completely ending things before we ever actually had the chance to establish what a relationship between us would look like.
He told me he wanted something serious with me.
I told him what I needed to feel comfortable moving toward that.
Then I saw behavior that contradicted what he said, got hurt, got drunk, and blew everything up.
Part of me feels like I protected my self-respect.
Another part of me wonders if I ran away the second things became emotionally complicated because that's something I've historically done when I start caring about someone.
I don't want people to just tell me "you deserve better" or "block him, queen." I genuinely want honest opinions, even if I'm the problem here.
Was his behavior enough of a red flag that I should leave this alone?
Or did we simply have a communication/boundary problem that could potentially have been worked through if I had handled the situation differently?
And most importantly:
Would you reach back out to him and have the conversation we never actually got to have, or would you consider this a sign that the relationship would ultimately make me miserable?
I don't want to reach out just because I miss him. I want to know whether there's actually something here worth fighting for — or whether I'm just having a hard time letting go of someone I became attached to.