Can someone act like my big sister and help me through this

We were together for fours years. I’m 19 and he’s 20. Known each other for 8 years, and we were constantly chasing each other until we ended up together in 2016. I moved away to my moms (4 hours from him) because of custody reasons. And haven’t been able to move back because of school and work right now plus of things like this.

He has this ex that he dated a couple months before we got together. She was popping up a lot in the beginning so I said it made me uncomfortable and he “blocked” her. They were in the same friend group so I understood that it was hard to cut off all contact with her so I didn’t think about it much. We were fighting a lot in the beginning of 2018 so we took a break and I slept with someone else ( biggest mistake of my life) I called him crying and apologizing within five minutes of it happening (don’t worry the guy already left 🤦🏻‍♀️) and he ignored me for like two weeks which I completely understood. He ended up taking me back. I did whatever I could to earn back his trust, and we worked it out. She started popping up more and he always told me that she was blocked. I never thought much into it because if he really wanted to be with her he definitely could’ve. We were long distance so I understood if he wanted to leave for a more physical relationship.

I went to visit him last week and she popped up again. At this point it’s been two years, My exes are all blocked. I’ve been completely honest with him for two years straight. We get Into a fight and I leave back home. I add her on Instagram and she messages me immediately asking if I have something to say. I say yes why do you keep popping up on my boyfriends snap. She said they’ve been best friends for four years so I should find someone else to fuck with, also he’s cheating on me, calls me crazy, and he’s going to break up with me. I said damn thanks for the info ig. I confront him and he lies to my face saying none of that is true and she only snapchats him to ask if he wants to go her baby shower. I break up with him and leave it at that. Her best friend ( one of my very very old friends also) texts me on Instagram saying she’s tired of him being two faced and playing both of us. Says he’s 100% cheating on me. I ask for proof. She sends screenshots of him saying “lemme come make you feel good” “I miss you, I wanna see you” “ I’ve been thinking about you” My heart is breaking because this is so out of character for him. These messages were from 2018. Then I see some from March of this year of him asking who’s baby it is, she says she’s pretty sure it’s this other guys but she’s going to get a DNA test when it’s born. Then I get videos of him at her house. I confront him and he lies telling me it’s not true so I read the screenshots to him and he finally owns up to everything except hooking up with her. Either way he cheated, whether he wants to admit they hooked up or not. She said they did but I don’t know her that well. He would talk to her about our relationship when we’d fight and go over to “smoke and watch movies” 🙄

Im heartbroken, I’ve been trying to compare what I did to what he did but he dragged his out for two years and mine was a one day fuck up that i came clean for immediately and he went behind my back for so long. I love him so much but I’m not sure if I’ll ever be able to trust him. I know I hurt him before and I probably deserve this but I swear I changed for the better and I proved that to him every single day to boost that trust. We had planned moving in together, kids, marriage and it kind of went down the drain. I want to forgive him and see if we can work it out the upcoming months but at this point I told him only time can tell if we are meant to be together. I just graduated with my associates and I’m trying to transfer to a four year university, I have a job to worry about and the last thing I need is to try to rekindle a relationship that might just fall apart in the end . Can y’all give me any words of wisdom? He’s been texting me nonstop trying to fix it but I’m not sure.

I strongly believe in the universe telling you when the time is right and when the time is wrong. All things point to this being the wrong person or the wrong time and I’m trying to find peace in that. I can’t tell my mom because I don’t want to paint him in a bad light, I’m the oldest sister and no one i know was in a serious relationship so it’s really hard to talk to anyone.