I have done it many times - intentionally hurting myself emotionally. The wounds are sometimes very deep. To me, it is not essentially different from physical SI, or other destructive coping. And it makes a lot of sense that emotional SI could follow from a history of emotional abuse. I don't know of specific resources about emotional SI, but I think that a lot of the same ones that are helpful for any kind of SI, destructive coping, or trauma recovery, might be useful. Also self-esteem. And this could be a focus or target in therapy, also.