As the parent of a child with ADHD, I completely understand your concerns regarding school, medications, etc. I would be frustrated as well.
One thing I do know is that if you put in writing that you want your child tested for learning disabilites, the school must follow through with this. It might help to check into what requirements there are in your state as far as following through and what needs to be included in the letter to the school.
I think it might help too, to post your question on our ADD/ADHD (more for children whereas this board caters more to adults) and Special Education Plans boards. The CLs and members on both boards are great about offering support and information.