He looks dehydrated. I do not know if this will help but I had one that was not getting enough water and I took her in the shower on a low mist. I stayed in there with her for a while. she started drinking after about 5 min. and I was able to get her going. I then started over the next few days giving her water from a bottle so to speak. she readily accepted and after a few days was able to start drinking from the misting again and made a full recovery. If it is dehydrated they go down hill very fast. I hope your able to recover him.
It looks like there are plants hanging from the mirror, when he sees his reflection in the mirror it will stress him out and he will likely get sick, the same plant seems to be appearing in all of the photos in different places please post pictures of the actual enclosure because I’m getting a bit curious.
He eats 10 crickets every other day and if he doesn’t finish them they are left for him the next day I also gut load my crickets before feeding him and but for some reason I’ve been having to how him his food so he notices it that’s the only way he was eating
You need a vet that knows how to treat chams and they need to run a fecal for parasites. For feeding him that much he should not be showing signs of being underweight which he is in the pic that you said he was healthy in.... Once you have seen a vet if you want to go over your husbandry to make sure everything is on point then you can fill out the form. But he needs a Vet Now.
Update he’s still alive and I called around the only place to take chameleons doesn’t have there vet cause she’s currently out of town so there’s that he’s still not drinking or eating and is now laying on his side