stuck

My boyfriend has gone behind my back 3 times now and gotten onto social media and dating websites to talk to other girls and at one point was even talking about being in a relationship with them. He's lied to my face about it multiple times and even blamed it on me because I didn't give him enough attention and stuff like that. We've been living together for a year now and I'm almost 29 weeks pregnant. I'm stuck because I can't bring myself to trust him. He still sleeps with his phone under his pillow and takes it with him/ hides it. But my job is here (2 hours away from my family) my doctor is here and I help pay the bills although his name is on the lease. I don't know what to do.