Hair twirling - 8 year old

Hello
My son twirls his hair aggressively while trying to relax, to the point that his hair is thin on his head in areas. He has always done it while watching tv, going to sleep, whenever he’s trying to relax. It’s like a compulsive habit, he does not pull the hair out but he wraps it around his finger so tight that it tugs on his scalp and sometimes hair falls out but generally he just creates a tightness sensation.
He is very active, hard to sit still, very slight so more underweight than anything, light eater, too busy to sit and eat, quite challenging to get him to sit still at dinner for more than 10mins. Well behaved but active, not rebellious or naughty, but very active. I feel he is exhausted easily. Tired often and burnt out. His hair is very thin on top where he twists it rapidly around his finger. He is fairly neat, likes things in order, sensitive emotionally. Very prone to eye chalzion and styes. Cries easily if he’s made fun of. Sleeps well. Often has accidents in his underwear not realising he needs to have a bowel movement until he’s stained his underwear then passes huge well formed bowel movements! Not sure if that’s any help finding a remedy. Thankyou for any suggestions.