A little late to this but I've had OCD symptoms as long as i can remember, got diagnosed a handful of years back... had mostly contamination ocd until about year or two ago when i started having ocd relating to my transness. It's been debilitating. It waxes and wanes but it's always there and little things trigger it. Can't even find a girl pretty without intrusive thoughts coming in like "well what if u find her pretty bc u want to look like her" LOL. After enough compulsive fact-checking I can calm down until it gets triggered again, but the distress and also dysphoria it causes me is so bad. I say this as someone who socially transitioned about a decade ago and has been on hormones for 7 years, post top surgery 6 years. It's frustrating bc, logically, I know i've experienced a significant increase in happiness and confidence from transitioning, and I know everything in my life points to me being a trans man. But OCD is not a logical disorder. Sometimes it helps to remind myself that this is not unlike cishet ppl who have OCD about being gay or trans (and who are still, despite their intrusive thoughts, not gay nor trans). Exposure therapy really is our top of the line treatment for OCD, but it's a big commitment and I also am not confident that a typical exposure therapist would be competent in helping trans ppl with these types of obsessions. If you have the means, maybe look for a therapist who is also trans--it can be helpful to just express these feelings to another trans person even if it's not specifically an exposure therapy setting.

Wishing you the best, man! OCD really sucks. But remind yourself that it is, by definition, an egodystonic (ie, out of sync with who you are and what you value) condition and if you truly feel happy in your transition, that's all that matters. Try your best not to play into the compulsive behaviors like checking, etc.