You received great advice and support on this thread and I am so glad you decided to post your OP. What I am going to write will reflect my bias against BDSM and ignorance, too, but it might help you on your quest out of feeling undeserving of life - think of yourself not as a victim of the girl who insisted you engage in practices you did not want to engage in, but of society as a whole that has long normalized these practices. You can think of the girl as a fellow victim. You were both victims. I am not against teenage sex in general, but you were clearly not old enough to manage what she believed needed to be done to her by you. Think of yourself and her as having the misfortune of facing a wrong rite of passage due to growing up in a certain place at a certain time. Get a reading list of love poetry from the yesteryear and read at list a little bit every day to get back to normalcy.