wreck my ds and I are dealing with the same, but we can afford private treatment and are doing that just now. Would it help to share what we're learning? The things they are doing are:
Talking through specific worries to find out what the problems are, and get it off our chest and think of practical solutions.
Talk about ways to calm down in the moment if things get tricky. This is very much along the lines of the 54321 thing that cag mentions or we do football commentary where we just look round and name what we can see, or name everything of a certain colour. It shuts down the imagination and grounds us in reality which really help with getting the mostly imaginary fears to buzz off just for a little while.
I'm also trying really hard to capitalise on those parts of our lives that are fullfilling and easy for us. So Beavers for ds and myself and my invention project for me, and the play dates that ds loves. Just generally I am trying to concentrate hard on those things that are good and to be kind of dismissive of the importance of those things that are not (PE and elegant social skills and stuff)
In our case I think there is a mild deficit in social skill that the professionals are trying to define in detail, in the hope that we will be under less stress if the actual problem is defined. I have an idea that your dd has more clearly defined challenges, which may or may not help.
Oddly we have also found a sport called footgolf that is doing us all a world of good. It basically involves kicking a football round a golf course and requires no skill and no speed.
These are the things that are helping us. Hope that helps.
Girlie thanks for the book title, I've ordered that.