First, there is hope, and children do get better. It's not easy and it's not a quick process, but it does happen.
You didn't give specifics about antibiotics and types of psychotherapy you've tried, so I'll tell you what's worked for us:
1. Cognitive behavior therapy for the OCD/anxiety. Traditional talk or play therapies aren't a lot of help in overcoming OCD, and behavior therapy will teach Evan what's happening to him and what to do when he has these intrusive worries and compulsions. You'll need to sit in on the early sessions so you'll be able to reinforce the therapist's techniques. He'll learn that OCD trying to boss him around, but he can be in control instead. [Tamar Chansky's books on OCD and anxiety tell how this works. They're available at Amazon.com.] Try to find a therapist who specializes in OCD specifically, not just in child psychotherapy.
Doing a search for a CBT therapist who treats OCD in children in your area, I found: http://www.lakesidecenter.org. Have you tried her?
2. Getting the strep eradicated. We found a pediatrician (on the psychotherapist's recommendation) who was willing to prescribe amoxicillin long-term (after a positive ASO titer). It took a month to see significant improvement. It sounds like your pediatrician isn't very supportive, so get recommendations and look for a proactive type of doctor.
Good luck, and please let us know how you're doing.
