I used to call my sh scars "physical representations of emotional scars". It always felt like when everything was too overwhelming and there was so much pain and sadness and anger inside me it was good to concentrate on something real. 
Physical pain&gt;&gt;emotional pain.
When my arm was hurting because I had put a massive cut on it, it felt much better than the invisible and indescribable feelings I had had before hand.
For weeks while they healed I could feel the physical reminder of something that was real and the pain was nothing in comparison to what went on in my head. 
I hid it so well when I started that my family didn't notice for years after. At least that's what I tell myself because I wore short sleeves and bloodstained jumpers so the reality is no one cared enough. No one was paying attention. 
I quit recently, cutting, not sh. It almost feels like I've lost a part of me, a crutch for when shit hits the fan but I don't miss the scars and I was getting too old to be doing shit like that. (19f) I'm not proud or anything.
Ig I just wanted to say this for people who don't understand sh. This is what I wish I could say to the people who point at my arm and ask "why though?"
Does everyone feel the same about sh?