I SI for actually a few reasons.

Low self esteem or blaming myself for something/general self loathing, stress/anxiety and needing to relax, feeling numb, feeling suicidal. Also it's probably to the point of addiction, as I haven't gone more than a few weeks without.

I always thought I was the only one who si'd because of suicidal thoughts/in order to prevent doing something more extreme. It's oddly comforting to know I'm not. Makes me feel a bit less weird.