I'm having a baby with someone I don't even know

I met this guy on tinder and at first he was absolutely great we lived a long way from each other but worked out a way to meet. Long story short we met up and hit it off immediately however he admitted to me that he isn't using his real name for personal reasons. He told me that he was from America and then a week later admitted that he's not. I at first wasn't entirely bothered about it. Now I'm pregnant I'm 18 and he's 22. I have since discovered that he has a lot of criminal charges and he has spoken to me about them now I feel like I can't trust him so much about him is making me feel uneasy and now he's moved into his friend's house near me. I can't stand to be in the same area as him. He has a very bad past and I've had people contact me saying he's not who he says he is and I am terrified of him. He has an extremely bad temper too. He has never put his hands on me but he has punched walls and stabbed a hoodie of mine in front of me because he went through my phone when I was asleep. He can be an absolute angel but all it takes is someone to say one thing wrong and that's it he gets set off big time. I don't know what to do anymore. He is constantly paranoid about me leaving and taking the baby and he always compares me to his ex who he has a daughter with however he doesn't even know if that's his daughter. I'm so conflicted I want to leave but I also don't want to. Please help?