Pastor T reminds me of a vet we used to see. My dog broke into a big itchy rash on his belly. We took the dog to the vet, and the vet gave us ointments and antibiotics and medicated shampoo. We diligently applied all the things exactly as prescribed. Didn't get better. Took the dog back to the vet, repeated this whole process three times. Eventually, the vet referred us to a dermatologist who said, "Hey, actually, your dog has a food allergy that's causing this." We changed our dog's diet to avoid the allergen, and he hasn't had a skin problem since.

I feel like self-harm is similar. You can focus on the symptom itself, but you are likely to expend a lot of energy without really getting anywhere. If you find somebody who can help you get to the root of the problem (which is likely trauma and not the self-harm itself), then you can heal a bunch of things at once and the urge to self-harm will go away more or less on its own.