Self-harm, but sexual. TW I guess.

Oh god. I can't believe I'm posting this. I don't even know what to say. First and foremost I'm being entirely truthful here and I'm not trolling or anything. I cut myself last month (on the wrists) for sexual pleasure. My brain is really weird and that's actually something I enjoy. I'm not going to pretend to understand the psychology behind it because I don't; I've just wanted to for years (and have before actually) and figured "why not". Fast forward to my appointment with my doctor last week, she saw the cuts and one thing led to another and she ended up having me illegally baker-acted. I was released once evaluated because she really didn't have valid concern or reason to do that, but one thing made my stay at the ER particularly difficult. They kept asking me why I did it and I just could not bring myself to explain it to them. I couldn't say it verbally so I asked for a pen and paper to write it down. Still couldn't do it. The most I managed to get out was that it was masochistic. I really don't think that conveyed the right thing. I don't even know what kind of advice I'm looking for here. I really just want to hear that there are genuinely people out there who understand this and don't consider it to be self-harm. I mean, it's still technically self-harm. But where do you draw the line? Ugh. To make matters worse, I think there are definitely some emotional ramifications involved in my sexual interests, and my masochism extends to all areas of my life at this point. So yeah, the lines are really blurred. How the hell do I explain this to a doctor or therapist? Is there anyone out there who can relate?