People develop obsessions because they “work” in some way. Apparently, self-harm distracted you from emotional pain. That’s a powerful reinforcer. So is orgasm. Put the two together, and you have inadvertently trained yourself to get off on pain. It’s effective, but it isn’t healthy. You know that. That’s why you wrote to us.
Either you still think you need the distraction or you have developed an unfortunate habit. Either way, if left untreated, the obsession will set you up for inviting more pain and will shadow your sexual relationships for a long time, maybe forever.
The good news is that obsessions can be stopped with therapy. Cognitive Behavior Therapy (CBT) has been shown to be especially effective if the desire for pain is a bad habit.
If, however, you are still avoiding something you shouldn’t avoid, then psychodynamic therapy is probably more helpful. If you are avoiding something to do with a traumatic experience, look for a therapist who specializes in trauma treatment.
I am very glad you wrote. The behavior hasn’t been going on for so long that it will not respond to treatment. You made a positive step in self-care by writing to us here at PsychCentral. Now, please, take the next step and get yourself into some therapy. Your school counselor can probably give you the names of counselors who specialize in teen issues. If you think you can’t afford it, think again. Many therapists offer a sliding scale. Group therapy is often cheaper than individual therapy. And there are often community agencies that provide services to teens. Check it out.
I wish you well.