Almost 40 years ago I was a professional pilot with Instrument, Commercial Single Engine, ATP Multi Engine, CFI, CFII, CFIME ratings. I left flying for a more lucrative career in technology and never thought I would fly again. I was diagnosed with ADD about 25 years ago because I was striving to be a technology executive for a regional airline based in IAD. While the medication really helped in very long and boring non-technology based meetings, had I known that I would want to get back into flying some day and that the medication could keep me from doing so, I would never have pursued that approach. Given the fact that I have already demonstrated the ability to complete the required flight and ground training as well as pass initial and recurring check rides, is it realistic to think that I could pass the battery of tests required. I recently retired and have been off of the meds for 90 days at this point and have no intention of ever taking them again. I am 67 years old and recognize that I probably only have a 5-10 years of flying left in me and am hopeful I can pursue it again.
You need to consult an expert in this area, like Dr. Bruce Chien (www.aeromedicaldoc.com). The AOPA Medical Help desk may also be able to assist. And there are no guarantees of anything despite your accomplishments before you were diagnosed.