In my humble and non-medical opinion, I think you MAY have bigger problems, but problems that can either be cured or controlled. You say you've always been a bit hyperactive and I'm just wondering as you enter adulthood if you may have Adult Attention Deficit Disorder. Please note that there are absolutely no letters after my name!
I think there might be a forum for that around here somewhere.........if there is, check it out.
If this "condition" is affecting your life or your job it's definitely time to see a doctor, which I think I would do anyway just because it's causing you some anxiety.
I seriously doubt there is any OTC med that would help and I strongly suggest not experimenting with anything until you have a firm diagnosis.
And if the thought of having AADD freaked you out, I know several adults with it and with medication they are absolutely fine.........happy and healthy and very CALM.
Best of luck