My skin-picking is out of control. Help!

NSFW cuz this is gross.

My whole life I’ve picked my skin. Since I was a child I’ve ripped off hang nails, scabs, bug bites, freckles/birthmarks, and more. Once I hit puberty I added acne to the things I picked. I’m now almost 21 and I still can’t stop. My body is genuinely ruined in so many places, but I can’t stop myself.

My scalp is covered in scabs that I pick at, any acne on my face will get obliterated. My chest and back are destroyed. I wore a low-cut top once and a concerned classmate said it looked like I was breaking out in hives on my chest; it was years worth of acne scars she was looking at. I have straight up holes in my skin, genuine craters. I have scabs on my pubic area due to ingrown hairs I picked. It’s so disgusting and I feel so gross all the time; I have to keep my nails short otherwise they collect blood and skin that won’t go away when I wash my hands. If I don’t have anything to pick at, then I bite the skin off around the tips of my fingers.

I’m a college student and spend my classes picking at my skin while listening to the professor. It’s so gross. I feel so gross and my skin is absolutely ruined. I need help! Any advice??