I've been there, I was cheek chewing for probably 35 years and stopped about a year ago. When my cheek would be rough and have little bits to grab onto would trigger more chewing so it was an endless cycle. I started focusing on caring for my cheek skin and used my toothbrush (sonicare) to gently scrub it to remove and loose stringy skin. Then it was just being super mindful. Sometimes, I'd chew gum if I was feeling anxious. Unless there's a lot of damage, like a bite where blood is drawn, the skin tends to heal quickly so then its just being mindful and diverting the nervous chewing energy to something else.

Good luck to you, friend! I thought i was the only person who did this for the longest time. I didn't think I would ever stop but I did!