I once almost self-harmed myself but I didn't...
During a past period of crisis several moths ago, I was so desperate my body was moving alone. My hands grabbed scissors and got close to my skin, but a part of me said "No, don't do it. Simply don't". My hands were still moving by themselves but I didn't get hurt in any way. After some minutes, the crisis passed. I have had one or two similar crisis lately, but each one with more and more reluctance to even think about self-harm. I talked about it with my therapist.
What I've learnt from this to cope with self-harm crisis, is to resist. Resist as much as you can to harm yourself, even when the weapon is inches away from your skin. Your body may continue moving, but the chances of reaching the harm are very lower.
That's already win. If you can, you can call an emergency number. Intense feelings don't last forever.
After those crisis, I realised I had been self-harming in other sitiations in the past. Being aware of it is the important first step to stop the cycle
@Politonno
Is lot more easy resist when never do before not easy like me self harm some way every day resist to me mean maybe not hurt self super bad just little bad does not mean can stop happen because already hurting self before realize what happening
I know that breaking the cycle can be hard. What worked for me doesn't necessarily have to work with you and that's fine. Seems you have been through a lot of pain too. You still are strong, you are counsious of what happens to you.