I let my girlfriend believe she is horrible for doing something I’ve done way worse

TLDR; I (22M) got dumped by my gf (22F) who wanted to “explore herself” after being in a toxic relationship for a year. I ended up sleeping with 3-4 girls after breaking up and never told her, she only made out with 1 guy that too when she was wasted and immediately told me about and felt horrible and I let her believe she is a bad person for doing that. We are now back together and she still doesn’t know the truth.

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I (22M) have been in a relationship for 2 year with my girlfriends (22F). I’m gonna toot my own horn in this, but this is the first time I’m doing it in entirety of our relationship and I kinda need to do that to boost my self esteem a little. I never yelled at her, or got mad at her. If I did I would remind myself how much I love her and fix my mood before she even knew I was pissed. She would take her anger out on me even when I didn’t deserve it.

She used to be the perfect girl for me, still is sort of. When we started dating I was crazy in love with her, I didn’t even feel the need to look at any other girl or even think of a future that didn’t have her in it. She, on the other hand, was sort of emotionally immature at the time. She said we weren’t end game, which was realistic since we were just 20 at the time and that was my first relationship, it was her 3rd (exes were very short high school flings). She would use me as an emotional punching bag, project a lot of things on to me, and I would sit there and take it thinking this behaviour is temporary she’s just going through some stuff and apart from these toxic traits she’s perfect, takes care of me, respects me, talks to me and looks at me like like nobody has ever done before. I loved her, for an entire year, and my love only grew for her everyday despite everything that happened. She acknowledged she was in the wrong and would try to fix things. I wasn’t perfect either, I hurt her and angered her many times.

Few months into the relationship she started saying she isn’t attracted to me and I tried to work on myself more and more so I could be the man she wants to be with and not stuck with only because she loves him. Only last week she told me she said all those things because she was insecure about her ownself and said all that as an attempt to somehow feel better about herself. Every single meltdown, every single fight, was just made up. That shit left me with deep rooted trauma only for it to not be real. That revelation has got me feeling I don’t know what.

Shortly after we celebrated our 1 year anniversary, she found out she is going to another country for a semester abroad. We celebrated that, and a few days after that she told me she’s breaking up with me because she feels there’s something more than me out there and that she wants to use the semester abroad opportunity to “explore herself” and maybe come back once “she has her shit figured out”(her words).

Everyone in her life tells her I’m the most perfect man out there, everyone in my life told me to avoid her like the plague.

After the breakup I had to travel to another city for some work. It was my first time travelling in a long time, and I started getting a lot more attention after fixing myself up a bit to the point I didn’t even look local in my own city. I had some friends with me too, and I didn’t want to be a party pooper who missed his ex and ruined the fun, so I tried to think of her as less as I could. I decided it to cash in on the attention I was getting and joined dating apps and I got insane response, more matches than my conventionally beautiful female friend was getting. I hooked up with someone, it was a one night stand but she ended up falling for me in the 2 days we hung out. I told her I’m leaving after 2 days and nothing will come out of it but she still tries to contact me time to time even though that ONS is blocked. I came back I got in contact with my ex again, she asked if I had been with someone and I lied to her saying no. I was scared that she’d get with someone else too as a way of getting back and that would absolutely crush me. To this day I admit I am wrong and immature, but I don’t plan on telling her about it ever. If she finds out, I won’t deny it.

Shortly after I came back it was time for her to leave and she left, only for us to get back in contact since she was feeling home sick and I was the only person she ever found comfort in. She told me she is on dating apps and would see people, but something happened and she never ended up going on even 1 date. I, on the other hand, was meeting new people left and right. Not hooking up, I would just meet them and cut them off cuz I would miss my (at the time ex)girlfriend too much. I ended up hooking up with 2-3 more girls but it was just that. I wanted to find my worth and I realised I could do better than my ex, but I wanted nobody else but her.