Glad you went to the vet,
too many people would "wait it out" and then it's too late.
Not to disagree with your vet on the setup suggestions, but for an adult cham you would need a very large tank. Tanks are generally not recommended due to the possibility of mold. You simply cannot get the ventilation they require (some people will disagree with me and that is why I said "generally"
Yes, it will help keep humidity up but maybe too much and you also have to watch temps due to the glass. You also then have the concern of him seeing his reflcetion in the galss, thinking it is another cham and will stress or try to lunge at it, hurting itself. I am not trying to add drama here, just pointing some important things out to you.
There are several ways you can keep the humidity and temps at good levels in a screen cage. I live in NH so we have long, cold, dry winters. I put a shower curtain around the cage on three sides as well as set up a humidifier which goes directly into cage and can be set with a timer.
Up to you, but I still think running your setup (maybe with pics?) by the forum certainly cannot hurt 
here are some pics of Luna's setup



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Chameleon Help & Resource Info
1.0 Nosy Be Panther Chameleon - Cyrus
0.1 Veiled Chameleon - Luna. She's now hanging from her big jungle gym in the sky
1.0 Beardie - Darwin
0.2 felines - Kyndra and Lita
0.1 African Clawed Frog - Skipper
0.1 Mad. Hissers and she's back!
0.1 Chilean Rose Hair Tarantula - Rosa Leigh
0.1 Goliath Bird-Eater Tarantula - Natasha
?.? Pinktoe Tarantula - no name yet