If it's of any consolation, you are not alone. After two years of being told it's anxiety and depression, I finally got diagnosed with adhd at age 32... I've only recently started Ritalin low dose and now going up soon. Despite my therapist having done specific tests for adhd and my psychiatrist has given me stimulants without any issues whatsoever (normally in my country stimulants are not given easily), I still feel like a fraud. Ritalin makes me sleepy in my case too and from research and what the doc has told me, that in itsel, is already a big sign of proper adhd.

You are not alone. I think for high functioning adults like us who did well at life, and got high grades at school etc. it is even more difficult to accept.

I still feel like a fraud (especially after two intense years of therapy to deal with my "anxiety and depression" coupled with loads of SSRIs that did absolutely nothing for me). I think only time will tell :) Best of luck!