To answer the questions.

My aquarium stile tank is 20 gallon size. I do keep a towel over the entire tank.

The cooler side fluctuates between 75 and 83 degrees. Under tank heating pad for the warmer side.

The hide is a little larger on the warmer side than the cooler side. The cooler side hide is snug. He does fit but barely.

Temp and humidity is measured digitally.

I think he is stressed.

I don't have a way to weigh him. I will get a gram scale.

I think someone said that feeding (2 and 3) in his cage is bad. Everyone said not to handle him. How am I supposed to put him in the feeding box then?