I don't know if this is the best advise, but it's what me and my gf did. We just went for it. We didn't move that far from our parents, but my gf didn't think we could make it on our own.

So far we have been on our own for almost two years, and things have been tight at times, and things have been hard, but I wouldn't trade it for anything. She doesn't really understand how hard things get with my illness sometimes, but she is supportive. But really, how many people that aren't going through it really understand it?

You can help him understand better if you try to describe things in terms he can relate to. I remember trying to describe a crushing depression to her at one point. She works twelve hour shifts, so one day I asked her how hard it would be if I told her she had to sprint 5 miles after she got off work. She looked at me like I was nuts. I told her that sometimes that is how it feels when I'm asked to just get out of bed.

I think you can do it if it's what you really want to do, but is what your mother is saying causing you to doubt because of what she is saying, or because there is already doubt in you? If the doubt is really already in your head, and what your mother is saying is just giving you a reason to voice your own doubts, then I would definitely hold off.