Caught boyfriend watching gay porn

Lately my boyfriend has been acting really weird. He's been super secretive about his phone. Every time i touch it he runs and grabs it then yells at me. I found out while i was at night school he tried to hang out with one of my girl friends, she said no but it pissed me off. I felt like he was cheating so I looked through his phone. TMI but The only time he has sex with me is if its anal or if I'm putting something inside of him. I found gay porn all over his phone! I don't know what to think. I brought it up and he said that he was making sure he wasn't gay so he watched it. Wtf? I dont know what to think.. Should I leave? He always accuses me of cheating, calls me names and isn't attracted to me.. I feel like he's cheating and it may be a guy?