KrazyKat: you might want to mark down a list of questions to bring to your appointment. I did that, and made a list of all of the things I had noticed that lead me to realize I might have ADHD as well. I was sure I’d forget otherwise (in itself, somewhat of a symptom!). That way you might not be as worried.
Oh, and it helps to bring a pen and a pad in with you as well, to make notes when the doctor answers you.
(And if you’re like me, and you think this is a good idea, your best bet is to get them out and ready now, and place them in a “speed bump” location so that you don’t forget. Otherwise – if you’re like me – you will. 
“Speed bump location” for me is putting them on my shoes so that I have to see them before going out)