Pain as Pleasure

A friend of mine recently recommended an episode of Black Mirror to me, in which a doctor is able to feel his patients' pain. The doctor finds himself enjoying the pain, to the point where he is unable to perform his job correctly. Eventually, he realizes he can enjoy pain by hurting himself, and the rest of the episode features him "cutting bits of his body off."
Though I'm not a masochist, or into self harming, I do identify with the doctor in some way. Take hot-sauce, for example. Plenty of people enjoy hot-sauce, and I can't speak for any of them, but personally, I enjoy the pain. I remember eating crushed ghost peppers sophomore year in track season: I told my pals it invigorated me, but I just enjoyed the pleasure I derived from the pain.
My first memorable exposure to enjoyment of pain goes back to visits to the D.O. as a child. As the doctor pressed and pulled the muscles in my neck and back, I found myself relishing every moment, especially the uncomfortable ones.
I should clarify that this is not sexual pleasure, but a unique, mild euphoria that is exclusively induced by pain.
Another similar physical experience is the use of a TENS unit. I'm not sure what these are typically for, but I have enjoyed many hours on the table at the chiropractor being zapped by this pleasure-generating pence machine. When turned all the way up, the TENS keep forcing one's muscles to contract, and can hurt quite a bit. At points, it's so pleasurable that I am basically laughing and drooling into the face towel while convulsing uncontrollably. It sounds disgusting, but feels extraordinary.
These physical pleasures are lovely, but they are nothing compared to the enjoyment induced by emotional pain. At this point, it becomes more about the aesthetic than the pleasure. Imagine an artist making a beautiful art piece, and then destroying it in a creative, unique way. Was the art the piece that was destroyed, or does the art encompass both the destroyed piece and the entire act? Obviously, half the artistry is the creative act of destruction