I need tips on stopping please!! I just CAN'T stop!!

I have been picking my lips and fingers (sometimes my face) since i was 5 or 6, I am 17 now. I have always tried to stop but it does not stop for long then i pick again. I notice i don't pick much in the summer but when school starts it like BAM, back. my hands and lips have scars on them. I just recently bought some nail polish to wear because my nails were nice but not anymore. I will start to wear gloves more often (like in the house and everywhere) but i don't want to wear them in school because people will stare and make comments and can't handle that. I have tried using a rubber band and snap it when i start to pick but it looks bad with red marks on my arms. What are some things i can do to try to help me- without medicine. I did tell my mom about this and she was like its only a nervous habit. I do it anytime, when bored,on the computer,at school,reading,watching TV, anytime. My fingers and lips hurt soo much right now is there anything i can do about it?