No advice here... But wanted to let you know that you aren't alone. I've had my male hog for just over 1 year now and he has been doing similar things to yours. He just started eating again over the summer, and then abruptly decided to stop about a month ago. I even setup a fluorescent light over his tank just in case lack of light exposure was causing it... Still no dice.

Good luck with your guy. Mine went about 3 months without eating in one stretch and did get very skinny. It can be very frustrating when you have all the parameters correct and they still won't eat.