Since currently you do not have a Uvb source, perhaps, cup feeding your chameleon for the time being. Break off the back (shin) part of their legs and stick them in a little bowl. Your chameleon will need that D3. Maybe even just hand feed the crickets to your chameleon.
Are you properly feeding and watering your crickets? Your chameleon needs a uvb source.
You were probably dusting much too much.
when we say dust, we do mean dust, not a coating.