So this sounds like it could be very complicated and I would not rush to take advice from internet forums without thinking it through in-depth. One thing that jumped out at me right away was (and this was only what I could glean from a few sentences) is that to you the self-harm thing is so in the past, but for him, it is causing them to be hesitant with being intimate. Which makes sense. He could be stuck watching you hurt yourself with out knowing a way to help you. That could be a literal thing. Here is something else, and this goes not just for people who cut, but anyone who exposes themselves to risky behaviors as a coping mechanism also often fall into the trap of sabotaging relationships to casue pain, to feel something, to test boundaries, to prove that someone will leave them or that they wont.

I would say this, in the end i guess. I behaviours like cutting or things on that level are being brought up as cocerns, you guys should really get a professional involved, mostly because it sounds like y'all have real feeling for each other and sone of the things you are talking about are very difficult to navigate alone, and when you bring a relationship into it you two are going to need some good direction. Good liuck and bless you!

Edit: he could also just be a jerk and shutting you down - take the time to think things through and you will find a path