Jake,
I think I *see* you if that helps. I also think that anxiety can mess with your ability to retain and process info. It sounds like you are a very high functioning person dealing with these issues, that actually takes a lot of work/energy that your brain could be utilizing for other tasks you may be having more trouble with.
I'm sorry you aren't having as much success with psychologists as you would like. I really think you're going to have to find one that is smarter than you. To be blunt, that may pose a challenge.
We take our kids to psychologist that specializes in gifted to assess for giftedness. I don't see any reason why you shouldn't seek out a professional that specializes in gifted/highly gifted.
I'll also suggest you take all and any evidence of any learning disability or cognitive functioning difficulty and schedule a meeting with your guidance counselor. Ask if there is any way they can help you. There could be resources available or perhaps you would be allowed extra time on essay tests, etc.
Hope this is helpful. Feel free to p.m. me if you wish.
Neato