I probably know what you mean by SI, but I've never heard it in that term... What does SI mean?

I've switched therapists 4 different times since my first therapy session when I was 12, and the one I have now is really good. She's really nice and tries helping me, but it's like nothing else can enter my mind when I'm in that cutting mode... It's like all rational thoughts leave for that moment, you know? She's tried helping me find other coping methods, but they all only worked for a very short time. She even suggested I wear a rubberband at all times and when I get that craving, smack the band against my wrist and I'll be feeling the pain, yet not hurting myself... But that didn't work for very long at all.