Sick of picking

I pick at the bottoms of my feet all the time I'm. I also bite the skin around my thumbs and nails but I'm getting better at that. My biggest fault is the bottoms of my feet. I will pick them sometimes until they're raw and bleeding and it's painful for me to walk. I have tried lotion I have tried pumice Stones I have tried electronic pumice devices... Nothing helps. I cannot walk sometimes... I'm 34 and I'm so sick of picking. I need help!!!