Seeing a therapist is your best course of action, Sharon- and again, not because you think you're "screwed up", but because they can help root out the real issue here. It's obvious that the impulses you're having are stemming from your low self-esteem. You're thinking that having random men have sex with you will somehow prove that you're attractive. As you saw, it doesn't work that way.
Your best bet is to seek this help in identifying the underlying issues from a professional. Lots and lots of people go to some sort of therapy for all sorts of reasons. Identifying the cause of the feelings you're experiencing is important, before you continue to be destructive towards yourself. The therapist is likely going to ask about the motivations behind the sexual encounter you had, maybe if you have a history of sexual abuse from your past, and why you feel so low about yourself.
The best thing any person can do for themselves is recognize a problem, and seek to fix it. No one can help themselves out of
everything; we all need a helping hand from time to time.
