I'm assuming he is in a glass tank? Sterilites are so easy to control the temps and humidity btw. A tank will not hold humidity with a screen top regardless of how many plants are in there and how much you spray it... I'm sure people will argue this but I've had chameleons in tanks before and found the only way to keep it humid is to cover the top with something other than the screen. Maybe just set a cut out heavy duty trash bag on top of the screen covering 3/4 of it to reduce airflow and retain the water. Put the water dish closer to where you have the UTH.
I am in the same situation you have with my female pastel. She was always in the chuck norris position ready to strike. Didn't even use her hide much. However I've found out that snakes won't use their hides at first if they are really scared and nervous. Once I found that out I only bothered her to change and clean her water bowl and to give her food. Unfortunately she is shedding right now but I can tell she has calmed down a great deal and if she wasn't in shed then I could probably pick her up and handle her. Like every one else has said, give her time to chill, no need to take him back.