I bite my nails and cuticles, as well as my right pinky finger

Hello, I am a 22yr old female who has been biting my nails and fingers since I was 17. My nails are not really what is bothering me, it is my right pinky finger. I bite my pinky incessantly, around the cuticle,the knuckle and the sides.I bite my pinky so often that it becomes raw and very red and swollen. I hid it from people for a long time because I was ashamed and embarrassed, thought people would consider me a freak. I finally gave in and showed it to my doctor at my last physical around 8 months ago and she told me I had a mild-staph infection on my pinky and prescribed me antibiotics. That scared me for a day but still didn't stop me. I love biting it because I feel such a weird calmness whenever i bite off a rough bit and chew on it between my front teeth. It's hard for me to even admit that here on this forum. My mum always tries to swat my hand away but that just irritates me and stresses me out more and makes me want to bite it more, and I put band-aids on it when I work but that just means that there will be more to pick off once I take off the band aid. I feel like this nervous sub-conscious habit is very detrimental to my health...I don't want to lose my pinky finger!! Any tips on how can I stop? Is therapy the only answer? I am so glad that this website exists and that I am not alone with this habit. Please help if you can, thank you :)