I'm new to the area so I have no idea what the state provides in terms of assistance and programs for families/kids with Autism. My sis in FL had the same challenges, but there was a lot of help from the state, but I think it may have been school related programs. I'd look into that, though.
You mentioned that you're very involved in your church - perhaps that might be the way to go re. help (legal and otherwise). There might be someone in your congregation that would be willing to help on a sliding scale re. the support issue with your husband. And maybe there are other families with autistic children that could become a support group with you.
I recently saw part of a documentary about the Miracle Project - autism and theater - I think the woman who started it was in a similar situation. It might be worth contacting them, even just for support, information, etc.