How to stop biting my nails
It made me 
How I did it: I bit my nails since I was like 6 years old and didn't stop til just last year. Its been really nice. I pretty much learned to handle stress and boredom better and not take it out on my fingernails lol.
Lessons & tips: Have more sex, lol (safely of course).
If you can't do that, there are other ways to manage stress that don't involve biting your nails. When I'm feeling stressed and overwhelmed sometimes it helps to write my thoughts down. Then if you have time, exercise, it helps too. :P
