picking and self-injury

Nobody knows about my picking and self-harm except for my sister whom I confided in last week. About 1/2 of my breast is a scab that I pick off every night. Even though it is trying to heal I just won't let it. I have sores and scars all over my body from picking but the one on my breast is "the jewel". I've never told my Doctor about it but I have an appointment next month and I have to get up the courage to tell her everything. I could lie my way out of it but I think it's time to tell the truth. I'm nearly 50 and have been picking myself since I was a child. I look at old pictures and I can see how long I've been doing it. A lot of times I'll create an injury. 6 months ago I poured acid on my arm which created a large injury. I've gashed myself with glass. Pounded my head against walls. I don't do it for attention, I do it to release all the pain and frustration. I always feel calmer after I've done this kind of behavior. I remember when I was in a punk band we were called "Babs and her Scabs". Everybody thought it was funny, including me, but no one at the time ever addressed the issue (including me). I did a search on Google and was interested in how many people are actually affected by this. I have a terrible problem with depression and many times I can't even leave the house because I'm just too afraid of people and what might happen. I feel like I'm just a big mess.