First of all, getting thoughts isn't what OCD is. HOCD is a description of a person who gets thoughts of being gay but doesn't like those thoughts. It isn't really OCD, but it does have a name and a diagnosis so it's out there. It's really a phobia about being gay, a very common thing after centuries of oppression of gay people. If you didn't have a belief planted in you that being gay or bi was a bad thing, the thought would just be one of those random thoughts you get every day and don't worry about. So that's why it scares you, because society does make it harder to be bi or gay. But humans have a brain that constantly generates all manner of thoughts. Every day you get a ton of them. So a good first step is to consider why this one, a thought you apparently have no intentions of acting on nor have you ever had such a thought you acted on, bothers you so much and again, it's because society has determined it's a bad thing to be. Science and modernity has determined otherwise but centuries of castigation don't go away quickly or easily. If you don't want to be bi, don't be. If you don't want to be a mechanic and you get a thought some day that suggests being a mechanic would be fun, don't be a mechanic. Now, that's easy to say and much harder to do, but I hope it gives you a little more depth to how you approach this. Your actions will tell you what your sexuality will be. Your thoughts will always come and go. When they recur and bother you this much, that's the problem to focus on. Peace.