Can you describe your set up? Info needed can be found here...
https://www.chameleonforums.com/forum/showthread.php?t=66
I won't even pretend to know what's wrong with him, but maybe some of the more experienced keepers can help you figure out what's going on.
This is a list that I found for STL vets. I don't have any experience with them though.
http://www.herpvetconnection.com/missouri.shtml
There is also the STL herp society, maybe contact them and see what they can recommend?
http://www.stlherpsociety.org/
Where in STL do you live? I...
Does that mean that when you put them on a branch, you have them facing away from where the cham is? Not to sound like a dork, but do the hornworms have teeth? Pinchers? Can you take a close up pic? I'm just being curious.
Adorable! The first pic reminded me of a T-Rex (I just watched Jurassic Park for the billionth time yesterday). The second pic looked like a "come hither" look, LOL.