That makes a lot of sense to me even though I don't have SI scars. I punish myself in other ways, but when people are being mean, unreasonable, impossible, etc., I do wish I could convey to them that I'm my own worst critic, so please shut the **** up! It's like, I can't take any more, don't you understand I'm already on the edge?
I've felt overwhelmed most of my life, from childhood on, trying to take care of other people's problems and ignoring my own. Finally I was able to tell one or two members of my family that I have bipolar. I think maybe they understand a little better that I'm not able to bear everyone else's problems too as I try to maintain my own stability. That's my equivalent of showing my scars and stop trying to be the bastion of strength to the world.

Hope you will get the support you need from the people who love you and the insensitive people will stay far away.