It is proven to be a comforting habit for you, something that has worked when nothing else has. It isn't sick that you are resistant to giving it up.

Maybe you could e-mail what you have said in your post to your T, or print it out and give it to her/him with the statement that you are not willing to talk about it, really. Because knowing the degree to which you do it, as well as knowing that you are unwilling to talk about it (at least at this point) is important for your counselor to know.

Don't beat yourself up about this. No it isn't healthy, but it also is something that you feel you need to do right now. As you continue healing and working, things will probably change. You feel what you feel. You are who you are. Just hold on to that, as you heal and grow.

One can definitely become addicted to SI. What you describe very much reminds me of an addiction. It also reminds me of me. I am 42 years old, and engaged in cutting and burning until I was 31. I recently had a very brief relapse. There was a time when I didn't want to give it up either. Then when I finally felt ready, I did it cold turkey. I had 2 brief relapses, but other than those, have been able to resist all urges, and even more WANTED to resist those urges. Healing takes time. You will get there, just keep plugging along.