I am going to guess that you have been molested/sexually abused growing up. There may have been some physical abuse as well, given your brief self-description. Whatever the case, it has your self-image spinnning like a dervish inside of your head, and has been wreaking havoc in every aspect of your life - but most specifically, your sexual identity.
As for a plan of action, I would love to give you a quick couple of steps to overcome such a heinous background. Unfortunately, a magic wand like that simply does not exist. Your life did
not skid to this depth overnight, and it is going to take a fair amount of effort (and comittment) on your part to rise above the traumas of your history.
The (seriously) only solution will be intensive therapy. Through the relaitonship with a therapist, you can begin the arduous process of discovering what is REALLY your idea, and what is being driven by the voices from the past. Too, you may also wish to begin with an anti-depressant to stabilize your mind enough that therapy can have a better toe-hold. Unfortunately, you cannot drink heavily with an anti-depressant.
Listen, the path you are currently on feels bad to you, but therapy will feel worse for the first little while. I tell you that to say that you should not give up once you begin. The upside potential is too great - if you can weather the storm of beginning to tear off some of the scabs of the trauma. Believe me, there is hope on the other side, but prepare yourself for a difficult journey.