Does skin grow back?

New here, hello!
I've been a wolf biter my whole life. I'm almost 21 and I'm very insecure about dermatophagia suddenly.
I was diagnosed with severe OCD at age 18, and I also suffer with trich (on my legs and chest) and dermatillomania (pushing things out of my pores, its really gross and im working hard on this one too)
I'm currently trying really hard to quit biting my fingers cold turkey, but I'm terrified the skin won't ever grow back. My nails are so so tiny, and my fonget tips are almost pointy?? I'm so inseucre about it. I hate my hands more than any other part of my body.
Anyone quitting: do they grow back? Will my nailbeds grow back, or will I be doomed my whole life?