Me (m22) and my boyfriend (m20) have been together nearly 3 years. I now live with him in his family's home. 

A bit of quick backstory, he's cheated in the past, a few times. I've caught him lying multiple times. He had a secret reddit and onlyfans where he was subbed to people and asked for free nudes, I get his email notifications bc hes logged in on my computer and I saw it that way. 

Recently I've logged into his Instagram and yubo (friend making app) and seen messages of more instances of cheating or attempting to cheat, speaking sexually with others, and even some of him talking shit about me. 

This is only one of many issues in our relationship. All of these instances date back to anywhere between 6 months ago to a year.

I have been cheated on in every relationship I've ever had and I'm utterly broken down. 

I don't feel able to leave, I've tried and he's convinced me to stay. I have many medical issues and Where I'm living with him I have all of my appointments and information and moving back home means going back on years long waiting lists. In that time, my health could dramatically drop. I can't pay for private care so nhs is all I got (uk based) 

I want to confront him, I want to make him show me his snapchat, bc I know that's where he's done most of it bc messages I've seen tend to go "add me on snap, it's easier" but he refuses to show me any messages from anyone. He's even convinced me to be open before and he sexted one of my best friends, and when I've asked if he's sent videos to her including me in the them, he's said no, and when I looked on Instagram, I saw he had. 

My best friend is now my friend again, she's blocked him, after finding out what hes done to me. I've been telling everyone I'm working on leaving but right now it doesn't seem plausible. 

I want to confront him with what I've found, but I know he's gonna spin it on me for logging into his accounts. I know I was wrong for that, but not knowing has been killing me, and honestly I've been looking for just one more reason to leave and never look back. This might be it.