Ive been biting my lips and cheeks since I was a little kid. I recently made a disaster of my mouth while chewing and it has been swollen and sore for days.

I am trying to quit this habit. However, Im not sure how to go about it. Ive been trying to keep my mouth busy by chewing gum, however I have TMJ so chewing gum makes my jaw very sore and painful.

From what I've read this problem is cause by stress/anxiety and is a form of self injury.

If you used to do this and quit how did you quit?
Also, what should my next step be? Should I see a doctor? Can they even help me with this?