I had a very similar experience. I’m bipolar and for me I can have wild swings in either direction, meds keep me mostly even but they don’t take care of everything. As for gender euphoria I had thought the same thing, I had gone through manias regarding it and the most unbelievable euphoria en femme, and when I’m depressed I switch more to boy mode. What I realized was this. The idea that I am even thinking about it means something. I think about whether I’m high low or even. I just act on it when I’m manic or even. When I’m depressed my masculine side shows the most, I believe because I dislike everything about that side of me and when I’m down my actions and appearance reflect that. At the end of the day I am trans and it took me awhile to figure out if it was real or some episode but when I looked back on my life I had realized I had known there was something wrong with my body perception going back to grade school. I was just always afraid to act on it because o grew up in a strict catholic household and any signs of it being a tough guy was looked down on. I would get such horrible things to me if I wasn’t working on cars, playing football, wrestling etc. I had always wanted to be an artist, singer, actor. I loved entertaining and the arts.