I would just try coaxing by attempting to hand feed. Get him to trust you as much as he can, and eventually (hopefully) he'll want to climb on you on his own. This will take time though, so definitely don't rush things! It could throw you further back. My cham is such a cuddle bug now, instead...
I couldn't agree with you more. I can't believe how dark these reptariums are. When I tried to move my baby chams into one of these they hated it with a passion (I actually have a funny photo of this)! Screen cages ftw