You do not want to be in a relationship where you have to hide things. Trust me. Take your meds. Your wife can get on board with it, or not. Her choice.

My wife was always fine with me taking meds but we had some fierce arguments about the fact that our oldest child also has ADHD. She just didn't want to accept it for some reason. Right up until said child started expressing suicidal thoughts. At that point, all I could say was, "Look, we can either let her keep going down the same path I went down at that age or we can get her the help she needs." Wife got on board pretty quickly after that.

I get not understanding what's it like to have ADHD. That's fair. But to basically trash a major part of your lived experience because they themselves haven't lived takes some incredible arrogance.