Ok, i dont really know a lot about hornworms and roaches, i usually just give him dusted crickets, but from your description he doesn't seem too unhealthy, just keep him hydrated and try focus on dusted crickets, if you still want to go another step further maybe give him some liquid calcium.
Well i think he has MBD. Maybe for these few weeks it would be best to move him, into a place without branches or anything, a container will do. Feed him bird baby food, liquid calcium, and water. Make sure he gets enough sunlight, you can feed him crickets, but dont feed him anything else.
put in some tissue rolls, the ones that are empty, just the roll shape thingy, crickets wil like to chill it it, and everytime u take them out u can just take the rolls, which will have some crickets
Is he active? and does he have his eyes open?, if he is really weak i would suggest him some baby bird food, thats what my vet suggested, and if he is eating crickets himself make sure he has enough supplements.
My panther chameleon turned and stayed yellow for a few days, his eyes suddenly went sunken and he was really sick, i am sure he does not have MBD or any Lung Infection, i am not sure what is wrong with him though, i just know that he has undigested poop. Thanks a lot guys you saves him once...
I forgot to say, i force feed him food and water, i feed him crickets dusted in calcium powder, his eyes are always open, his eyes are big and healthy, his poop is also good. The vet said all his calcium levels and other stuff are normal. he is a bit overweight because i used to feed him a lot...