Not sure this is in the right place but if it reaches and helps one S.I. That would be good.
I read that to get the same 'hit' that S.I. gives without the harmful effects, there are 2 ways to satisfy the urge to injure oneself.
(1) Wear one or more tight elastic bands around your wrist. When the need to self harm, ping the band over and over again. It hurts but does not injure you.
(2) Hold a fistful of ice cubes in a tightly clenched fist and squeeze hard. Feel the hardness and coldness of the ice 'burn' your skin. Keep your fist tightly clenched as the ice melts, the burn and the ice melting is the release. If you substitute the need to see blood flowing with the resultant ice melting and flowing through your hand. This gives a visual release as well as a 'harming' release, without injury.

Hoping this may help.