As Coolio Tiffany already stated you should have started off with a hatchling but thats not the case so there are a few things you can do. If you don't have a hook-get one. Everytime you go to get him out of the cage tap him lightly on the head then gently pull him over to the door of the cage with the hook and slowly take him out (take your time and don't make any quick movements)-over time he should begin to realize that the tap on the head means its time to come out. I know you said you have the proper husbandry but recheck his temps and make sure he's not to hot. You can cover his tank with a blanket but you can also try and cover half of the window with that blue painters tape so it will block off half the cage and give him a better sense of security (don't cover the whole thing then you won't be able to see him) or you can get him a hide-big cardboard boxes work well until they get on top of them and crush it. And as everyone else has already stated-have another person present when you handle him.