Hello and welcome to Psych Central! Let's hope when his mental health gets better he will be ready to come back home to you.
It is unfortunate that his mom is so involved. After all, I assume by now that you are his common law wife. I assume if you were officially married, then you would have legal precedence over the mother. But, anyway, let's also hope his mom will back out some as time goes on, if he does improve and want to come back.
So sorry you are going through this all.