As Cory said, please post the 'Trouble' answers so we can give you better advice.

Also, how big/old is your pac? If you're feeding 5 crickets a night I don't think he would have had time to stop eating for a dangerously long amount of time in two weeks... That could just be a function of him getting older and needing to eat less often.
The flipping over and closing his eye does raise some flags though. Flipping in pacs can be a sign of extreme stress or illness.