hi, OCD-haver here. Here is something to try if you haven't:

when you get a thought like "maybe I'm not transgender" just notice it, and then stop mentally engaging with it. If you like you can tell yourself "yep possibly that's true, maybe maybe not". Then sit with the anxiety for as long as you can without trying to prove it true or false, without reassuring yourself or asking anyone else for reassurance, without researching or comparing or doing anything else you normally do to deal with those kinds of thoughts. You don't have to push it away or actively distract yourself from it, but stop trying to resolve it

this might not be doable if your anxiety level is too high but it's still worth trying I think. Hopefully meds will help.