my boyfriend has emails from dating apps

I caught my boyfriend with a snapchat full of girls a while back and stupidly forgave him. I just got paranoid he had made it back and went and looked at the email that was connected to it on his phone. (I know I shouldn't go through it) The email doesn't get much mail so I saw where he got an email from two dating apps over the summer while we were long distance. I confronted him and he started screaming at me that he isn't doing anything so leave him the hell alone. I'm going to try to get back on his phone tonight and log into them using his email. I've isolated myself from everyone I love for this guy and I'm terrified. I don't have any friends and nobody to talk to besides him. I don't know if I'll ever be strong enough to leave because I'm scared of being alone..