HI R.,
I am outraged at that school counselor and agree with you that ADD/ADHD is WAY over diagnosed right now. There are many many other things that look like ADD and aren't. That said, ADD isn't a curse and the ADD/ADHD brain is special. Handled well, ADD/ADHD kids can be very cool (as someone else said, they are often very intelligent, but their brains just function differently).
Have you sat down with the teacher and asked about specific problems/behaviors that he or she is noticing? I would then talk to your son about them and ask him what he thinks would help. Kids often have great insights into their own problems but as adults, we often forget to ask them. If the teacher does not seem sympathetic or willing to work with you, find out if there's another third grade teacher, or what other resources the school has. If they have a good school psychologist who is willing to help teachers work with kids in the way that helps them learn best, that's a huge asset. Often teachers are overwhelmed and don't know how to work with kids with behaviors that take a little extra effort on their part. I would also recommend an appointment with a child psychologist/psychiatrist asap.
You can request an IEP from the school (Individualized Education Plan). Write them a letter and I believe they have to accommodate your request within 60 days. In the meantime, there are organizations that help parents with IEP meetings - it can be very intimidating. I know Family Focus Empowerment Center at CSUN is one that will help for free and there are others - some you have to pay for.
There are lots of great resources out there if you have the time to do some research and you're already doing the most important thing - taking an active interest in what's happening to your son. He will know you love him and care about what happens to him, which is so important for his self-esteem. Good luck.