It sounds like you and I have a lot of parallells in our situation. Although she has never forced the issue with my family, she never has anythig good to say about them & anytime we are due to go to see them the few days before are always tense. But with the friends, I fully understand. The limited social contact I had was at work and of course they were all jerks & I was acting just like them & if I worked with a female, no matter what she looked like, it was just a matter of time before I started having an affair with them.
As far as going to the doctor with her,unfortunatly that is her choice, I think it would be a big help if you went with her, it has with me. Before when she got home I would always hear about how they said this and that about what I should & shouldn't be doing I would later find out that a lot of this wasn't true), but I also knew she wasn't telling the therapist everything that was going on with her either. Try to spin it a little like "I want to go so they can help me find better ways to support you" or something like that. I don't fully know your situation, but I bet that if it was her idea for you to go then it would be ok with her. I have learned that unfortunatly you have to do things like this to get the results you are looking for. I know that sounds awful, but the overall goal is to help them & to try to make a peaceful existance for the whole family. I have found that having a spouce with this is a lot like having another child sometimes & sometimes that is the way you have to deal with things.
Hopfully she will come around and let you start going with her, but it may take a while before she does, until then just try to stay calm & let the things she says roll off of you ( I know how hard that can be, especially when it has been all day) and come here often & just look around at other peoples posts & replies.