I chew the inside of my cheeks. I've always done it, but lately it's out of control. It's giving me headaches as I'm making my neck /head tense as I pull my cheek into a suitable chewing position.
I used to bite my nails, but stopped that years ago. If I don't chew my cheek, I can feel a build up stress/tension in my jaw/shoulders until I've done it. It sounds stupid I know. Sometimes I distract myself, however I tend to end up chewing later when I'm not thinking about it.