@bjkmom -
I tried the do the easy, fast ones approach with my oldest son when he was third grade. Boy, did it backfire - he spent the entire test trying to figure out WHICH problems were the easiest for him to solve and failed the test. He is mildly Aspie and very literal. The approach did work with my other kids, but with the oldest, I had to tell him to take the number of problems on the test, divide by the amount of time for the test and allocate that amount of time to each problem. If he finished a problem early, he could use the extra time later on. That worked better for him.
As for the OP - I agree that some counseling might be a good idea. This is a very stressful time of life.