Sad..venting

My boyfriend of over 1.5 years and I have been fighting so much lately. Over the summer things were amazing. But in September I moved in. And around October til now we just fight constantly. Then sometimes things are good and I'm so happy, but a day or two later we're back to fighting. He is the love of my life and we've talked about marriage and having a family but now he says I'm not the one for him and he doesn't feel that it will work anymore in his heart. So he wants me to leave but now I found out that I am most likely pregnant. He said he will find a way to make it work if I really am because he wants the be in his child's life. But I feel terrible to think that the only reason he would stay with me is for this. I just want things to go back to how they were. I love him so much I can't picture myself with anyone else or him with anyone else. It breaks my heart. But he just says how unhappy he is with me. Mainly because I'm all into his businesses because he's cheated before (a year ago) and I still find myself with anxiety fearful he will do it again. But he has changed a lot and wouldn't ever do it again but I still struggle with that fear. So that is what is tearing us apart and now with my emotions being crazy I'm even worse and he doesn't really understand that and just thinks I'm crazy as a person. I'm just so lost. I don't talk to my friends about this. Sorry this is long. Vent over ?