Am I having OCD or any other mental illness?

Unfortunately, yes. I'm no doctor, but I have OCD as well. It's not fun. The reason you are constantly washing your hands is because you are getting anxiety. Basically, if you don't wash your hands, you feel like you are going to get germs, so in order to relieve that feeling, you wash your hands, constantly or take too many showers. The reason you are questioning your sexuality is because you are afraid you might be homosexual or that you won't get to date a guy but don't worry about that. The sexuality thought is probably not OCD but it possibly could. The washing hands/shower to much thing is unfortunately OCD.