@cf05 For a period of time, yeah I’d say that it did feel more real than what I identified with. It was just constant questioning, doubt and comparisons. Exactly like you, I knew I was straight (as prior to this I’d never even considered being gay) but that doesn’t matter to OCD - it preys on the slimmest uncertainty.
I obviously don’t know your full situation, but based off what you’ve said, I’m very confident you’re straight. The fact you feel so strongly agansit being gay is evidence alone - you wouldn’t resist/obsess over it to this degree if you really were that way inclined.
I’ve been in your position and I promise it does gets better. OCD really is a terrible bully and will have you believe you’re something that you’re simply not. Like I said in my previous post, really do your best to accept the thought as just that, a thought. Perhaps label it in your brain as ‘intrusive thought’ or ‘OCD thought’, then let it be there (without following the thought down a rabbit hole), experience the anxiety/negative feelings, but then try to leave it at that. Like you say, the more you try to argue/reason with it, the stronger and more persuasive it seems to be, so do your best to let them be.
I hope that helps you slightly and remember, things do get better. I’m proof of that.