Transport Canada is notoriously tough on ADHD, but it’s not always a permanent "no." I've seen people in similar spots have success by requesting a formal "reconsideration" or a review by the Civil Aviation Medicine Review Board (CAMRB). Since you’re off meds and performing well, the key is usually a battery of independent neurocognitive tests (like the COGSCREEN-AE) to prove your functional capacity. It’s an expensive, uphill battle, but several pilots I know eventually got their Category 3 or 4 by showing years of stable, unmedicated history. If Canada remains a dead end, looking into the FAA in the U.S. is a common move, as they've recently updated their protocols to be slightly more streamlined for well-managed ADHD cases, though it still requires a mountain of paperwork. Stick with it, if your academic record is solid, you have the best possible leverage for an appeal.