Strong 2nd to Amalthea's adhd radar ping. The ones that leaped off the page for me (out of several), were the patterns with HW, the "if it's not perfect it's not going to happen" type of perfectionism, the cavalier attitude towards/near nonexistant internal structure (like daily tasks... we adhd'ers have nearly no internal structure, we have to create it externally),I'd recommend an eval to rule it out if nothing else... because adhd solutions are often the opposite to "normal" solutions. For a good into/look I'd also rec. the book "You mean I'm not lazy, stupid, or crazy?!?" by Kate Kelly & Peggy Ramundo. It comes from an adult perspective... so it's a lot better "grasping the big picture" tool than most anything else out there. If reading through you see your son page after page... well... it makes the idea of looking at an eval a more practical one. And the book's only $10. Versus the cost of an eval.
PERSONALLY... if it we me, or my adhd kiddo... I wouldn't quit the sport, because it USED to be fun. it probably can be again, but instead look for a different dojo FIRST. There are approximately 15 (good) gymnastics gyms in my city (there are scores of bad ones)... and out of all of them only ONE is a good fit for my kiddo. He's terrible. Really. As in bad. It takes him 2 years to move up a level it takes other mediocre kids 6 months (and talented kids 1-3 months). In addition to that, he talks almost nonstop. Either would drive serious competitive coaches up the freakin' wall. But he LOVES gymnastics. He has this big grin on his face the whole time. So there's this one gym where they have their competitive gym totally separate from their rec gym. And the coaches in both are PHENOMENAL. They love my son, and it shows. The Rec kids, they only care that they're learning safely and that they're having fun. It's all about having fun. If a kid has drive they'll try them in the competitive gym... but they're always welcome in the rec gym. One isn't held as better than another one. They have 2 different goals. We've been there now for 5 years. Love love love this gym (and as a former competitive gymnast I've got high standards). Snowboarding, on the other hand, we're in the opposite boat. Kiddo is GOOD. So the competitive coaches WANT him. But kiddo is still goofy/ flighty and apt to interrupt with a "Wanna hear something funny?" and launch into a story about spongebob or halo without taking a breath. He's not a serious kid. He's a goofball. There are only 2 coaches on the mountain who dig this. So we stick with them (yay Dilon & Mark!). Because no matter how good kiddo is, or how bad he is... if he's not having fun, we may as well have stayed home picking our noses. Actually, it would have been more productive to have done so, because we/I wouldn't be dealing with meltdowns, plummeting self esteem, etc... as kiddo plays over and over in his mind everything "wrong with him" or that he's "not capable of". And believe me, the wrong coach who does negative reinforcement instead of positive reinforcement bleeds over into all areas of kiddo's life. ((For anyone who says that he's going to just have to learn to deal with negative reinforcement... I ask them to look at their own adult lives. How long do you stay at a job where your boss has nothing good to say to you, where going to work makes you sad and angry, or feeling less than? How long do you stay in a relationship where you feel put down all the time?))
Anyhow... there are no answers in what I've just written. Just our experiences.
I think kids have good internal sensors. They know when they're not wanted. They know when they're looked down on. For some reason, we try and train this out of them. I have no idea why.