It's so difficult to stop this picking :(

Hello, I'm 23 and I have social anxiety pretty bad so I'm sure that is part of it. But I've been picking the skin off my fingers and cuticles since I was 6. I really want to stop this since its so embarrassing to show others my hands. I have got negative reactions to it several times in the past from family and friends. Some are a little more understanding but still pretty embarrassing for me. I honestly have no idea why I do it exactly. I do know it gets really bad when I'm stressed and upset or really angry about someone or something. I get lost in thought and find myself picking my right finger or bottom of my right heel now. I cannot stop until I either feel a burning sensation in my finger or my heel feels smooth again. Then I can't use my right pointer finger for awhile as it is sensative to grip with :( It isn't as bad as it used to be, I use to pick all my fingers and both my thumbs, random surfaces all over my body but I've stopped doing a lot over the years. My hands are healed from it now except my right pointer finger and my feet. Sometimes I just do it out of boredom and habit while most of the time it is when I'm feeling a negative emotion. As I am feeling right now and just picked my right pointer finger raw. I'm seeing a therapist for my anxiety but she isn't aware of my skin picking habit. I just want to be able to stop picking for good. Not have these random outbursts of picking sessions when I'm feeling negative or stressed about something.