He's a little over 2in and still looks fairly plump.
I had a little more luck last night. After trying for 15 minutes to get him to eat either a dubia or a piece of night crawler I took him out of his enclosure and put him in a deli cup with the roach, and he finally took it in there (but he wouldn't eat more than one). Can I put him in a deli cup every night and feed him that way or is it too stressful?

Also about heat, I'm worried he's not getting warm enough and it's affecting his appetite. Under his lamp it's always between 80-82 but he's usually on the other side of the enclosure where it's around 75 and he doesn't move from there. Is this alright?