Need help with picking

Just to make sure, i have autism and add (plus more) not adhd and i hope thats ok?

Im a serios skin picker, nail biter/picker, and chewer. i chew anything BUT chew toys bc i dont like the way they feel.

my nails are so fragile and small they break easy, theres barely any nail and it hurts my thumbs just typing this 🙁 im wondering if any other people like this have a healthy way of stopping, ive tried nail polish gross icky stuff- doesnt work, and i can bite my nails while chewing gum. im just sick of getting blood stains on stuff cuz i dont realise my nails are bleeding again. can anyone help me out? /please no critisism :(