So sad. I don’t know what to do

So my current SO is unlike anyone I’ve ever been with. The problem, the common denominator in all my problems is my mother. I wish they never had to meet or that she didn’t treat me like she did and does but he hates her. Doesn’t want anything to do with her. That’s fine. I’m 35 and when I’m able to move out again I will not talk to her again. She found out where I’m working and he thinks that when I leave she’s going to find me and then find where I am in general. He’s been so annoyed to the point he’s taking it out on me not trusting what I want for our future. He’s got his own things to deal with but he’s so focused on my idiot mom. I don’t want to lose him. She’s the only thing we fight about. We literally don’t fight about anything else. But I’m afraid he’s going to go and I don’t know what to do. I don’t want my mom in my life after a really bad past and present but at the moment I am stuck. I got a new job and I’m hoping to be out in a couple months but now I’m scared he won’t. We just fought about it again and he is off to work and won’t talk to me. I’m so sad I don’t know what to do with myself. It hurts because everything I’ve ever said I would do I’ve done and this is no different. He always says he’s not leaving me and will give me the chance to do what I say but I wish he would drop the subject until I can finally go. Anyone else have a parent who is too much and makes your SO crazy? We’ve been TTC and we were quite on time this month and if he’s going to go and I do get pregnant I’m scared.