K.,
Don't feel like a failure. (I hate it when educators do that...we have a principal like that here...take it with a grain of salt.)
Is okay, I've been there. However, get him tested. See what they say. Don't be afraid to see. And don't be afraid of meds. I thought the same thing you did at first. Then the doctor explained to me, what would happen if I didn't. His phonetic learning would not develop and by third grade, we would have set him up for failure for the rest of his school career. Trust me, my son was in K5 when we learned of his ADHD.
We now have a handle on it and he is in the first grade. We have good days and bad days. It will never be a fix. But go for the testing at least before you make any big decisions. Find out if he has it or not. Then decide. The decision for meds is ultimately yours even though you go through the testing. But keep an open mind. I walked into the office with my mind set, and came out with a completely different attitude. You just want the best for your child of course!!! We all do!!!
Good luck and God bless!
Lee