Warning-pretty descriptive!

I understand your feeling of comfort with cutting. I used to do this when I was young. Instead of just cutting I would work slowly with a sharp edge to carve things in my arms and watch the blood form whatever I had cut.
That was many years ago-now, many years later, my t says a behavior I sometimes practice falls into the same category. I sometimes take too many benzos and drink, even though I know where this could lead.
Btw, I am not doing any of this now, nor do I have the desire to do so, but just a few months ago I was in the same place as you.
Try to resist the urge to cut, and be honest with your t and pdoc. Let them help you to get this in control.
Good Luck!
Bluemountains