Rough morning

We've all been there! You're not alone. I'm straight and married and have still had the same panicky jolts and fears that you described (similar situation, too). I remember checking and double-checked my fears to see if they held any weight. Just remember that the more attention and reassurance we give those fears, the more "alive" they become. We give them weight. We give them sticking power. It's the opposite of what we want to do, right? Try not to keep testing yourself. If it happens again (and knowing OCD, it will!) try more ERP. Try saying something 20 times like, "Yeah, it's possible that I think she's attractive," until you feel desensitized to the thought. That's how it loses it's heaviness in your mind. It takes practice but it helps. Before you know it, you'll just note someone's attractiveness and move on with your day like everyone else. You can be straight and still notice that someone is good-looking, sexy, or gorgeous. It doesn't mean anything different about you as a person. You know who you are deep-down. It's OCD trying to mess with you and make you doubt yourself.

I’m a straight male and yesterday night on a gaming chat platform, a man was flirting with me as a joke because he knew it was making me feel weird and uncomfortable and I presumed he was gay and I blocked him immediately. I was so angry and frustrated. I immediately left that server because I don’t want to be hit on by guys. That’s not the life I ever want

The way my therapist explained it to me is anything you try to do to relieve anxiety, reduce uncertainty, to know for sure, is a compulsion. You have to ask yourself what is the function of the behavior? If it’s to make you feel relief, it’s most likely a compulsion. Are you working with a therapist? A therapist could be really helpful in designing ERP for you.

Unfortunately all of the behaviors you are doing "to be sure" are actually compulsions which keep OCD going strong. Allowing the uncomfortable feelings that accompany the doubt and uncertainty is the way out of the OCD cycle.