I cannot believe that the only social skill group they have in your town only takes children on Medicaid. I am totally spoiled by living in a large suburban area with many choices.
Indigo is like an encyclopedia of all kinds of resources.I am sure you can learn a lot by following her links.
I also wonder whether you can organize some sort of an unofficial social group. My son goes to one where they just play board games together. They somehow create situations that the kids are challenged socially. The idea is to learn to accept certain discomfort and to deal with it in a more acceptable way.