Break up over incompatibility—how to move on?

So I recently broke up with my boyfriend of four months (short time, I know), three days ago and everything is still fresh. For context he's two years younger than me and has two more years of college ahead of him while I just graduated this May.

We could have ended it cleanly at the end of classes, but he visited me for graduation and got to meet my family and I think that deepened things between us. To add more of a kick, he's going abroad this Fall. And, while I'm back home figuring out what to do next with my life, he's doing research at a lab that's pretty far from me, so our relationship after I graduated and for the foreseeable future had to be long distance.

The problem though is that he was a horrible communicator and I don't say this to justify it but he really is the kind of person to leave his mom on delivered for weeks at a time and just detach himself from his phone. We already had fights about it this Spring and earlier in the summer after a particularly bad lack of communication. We had a big call and I was ready to break up then and there but I wanted to give him one more chance because he explained himself and I could see where he was coming from. We agreed to be more communicative and that he would show up in the ways I needed to feel reassured and loved.

And he was good, he was better about texting and calling and would explain why he'd be radio silent. But, as time went on and as I talked to my friends, I started to feel that if this was his max effort, it still didn't feel enough.

I was hanging on at the end of each day waiting for his name to appear in my notifications. I would hate him for not texting me but then feel everything was right in the world when I finally got a text from him. I started to question why he didn't hype me up the way I did on his socials or in texts. I started to resent how I always had to initiate a call or text. I didn't want to have another conversation about asking him for the bare minimum of what I needed because I guess in the back of my mind, I started to realize there was no point. In two weeks, I would have visited him but that plan was idealistic from the start.

When my best friend visited me recently, I saw how he was with his boyfriend. And for the first time, it really sunk in with me that I needed something better than this. I couldn't take the emotional turmoil and guessing of his whereabouts. I couldn't take me pushing aside the boundaries I expressed to him when he didn't text me for two days yet again, even when I tried to understand and give him the benefit of the doubt time and again. That and the realization that he still had two years of growing to do and our relationship would have to end at some point before he went abroad.

I broke up with him on the phone and I didn't expect him to get defensive and take the tone he did. He said I love you to me for the first time before we ended the call and that he would always care about me. I thought about it so much. I texted him I loved him too later that night so he knew that what we had was real and that I would always care for him too.

Now, I just realized he's unfollowed me but kept me as a follower on IG. I'm so sad I'm hurting him like this. I want to just hug and kiss him. But I also know that we both deserve better and I have to trust that choosing myself feels wrong but is right for me in the long run.

I need advice and honest feedback, especially from people who don't know me.

TL;DR: Incompatible communication and timing didn't line up, hurt between us when I thought it would be otherwise. Lost with how to move on.