The question is, why don't you want to be bi? I think you are just shared of being judged and emasculated. But does that mean you really want to deny some strong feelings you may have. You may try to forget these feelings, but if you are constantly feeling them for diffeent males I think you may find that even if you deny them, you will be with them for life. A lifetime or ignoring some of your strongest desires? Well its up to you.
Even if you are bi, it doesn't change the person you are. You don't just magically change your dress sense and waltz into gay clubs. It just means you may be sexually attracted to guys and may experience some things with guys or girls. And if people choose not to accept you for who you are then that is there problem, but don't make it yours.