His mom is getting in the way

My story is really long and complicated. I've tried to make it as concise as possible, but I might be leaving some things out. Sorry... My boyfriend and I have been dating for about 3 and half years and at first everything was great. We moved in together after a year and a half and it was wonderful. However, his mother is ultra conservative and even though I thought we should tell her before we made the move (I told my parents who are also pretty conservative), he chose to wait. This continued for a year, and things were going well. We were starting to settle down together and seriously plan on getting married. I should point out that we were both in school and decided to wait until we were both graduated and had jobs to actually act on those plans because we wanted to be able to afford a wedding. Then his mother found out that we were living together. She immediately flipped out and threatened to never have anything to do with him again unless he moved out immediately. She made good on those threats by sending his father with a moving van to our apartment a few days later. He was unsure of what to do, but I believe that family is important and I figured we could live apart for a year while he finished school, then get married and be together once he got a job. I thought the only problem was that we were living together without being married, and I was glad to live apart from him until we were if it meant his family would be a part of our future, so I encouraged him to pack his things and leave with his dad. It's been almost a year since he moved out. He has graduated and is looking for jobs, but after a recent conversation with him it seems that the original plan isn't going to happen. It seems that his mom doesn't want to have anything to do with me even though we have gotten along well in the past. She believes that because I don't hold the same conservative beliefs as her, that I am not a christian, and she doesn't want anything to do with non-Christians. Ironically enough, I would have considered myself a christian before all of this happened. Now I am doubting because if she is really acting on God's plans like she says she is, I don't want anything to do with a God that would cause so much pain. I want to tell my boyfriend to just leave. It's making us both miserable and every day it seems less likely that the relationship will be repaired. And while my boyfriend agrees with me, he can't leave. On top of her ultra-conservative beliefs, his mother is mentally unstable. She had an extremely bad childhood and was abused and neglected, so it's understandable. However, it means that my boyfriend feels like he can't bring up our relationship with her, or the possibility of his moving out without her attempting to harm herself or others. She has also refused to get professional help. It's a scary situation and right now there seems to be no way out. I'm finding that I don't know what to do. I never planned on dating or getting married, but there is something special about this boy. I love him so much. I know he loves me and wants to be with me, but we are stuck because of the situation with his mom. He has been saying all along that he won't let his family get in the way of us being together, but that is exactly what is happening now. I feel like it's my fault for encouraging him to move home when his mom demanded it, but I didn't have a good understanding of how messed up his mom was at the time. I wish I could have a do-over and tell him to stay instead, but I can't. I don't want to break up with him, but I don't want to stay in a relationship that has no future either.