Why is my Corn Snake not eating?

[Rick]

I have had a corn snake for about 5 years now. He's always been healthy, always ate his food and shed his skin fine. But about a month and a half ago he shed his skin in flakes and not one full length of himself like usual. After that I gave him a bath and the skin came right off. I put a mouse in his tank the next day. He lunged at it, rapped around it kind of weird, and the mouse wiggled free and ran away. It stayed in his tank for about three days before dying, then I got rid of it. (The mouse, not the snake) The next time I tried to feed the snake, he stuck his tongue out, went forward slowly, opened his mouth and then closed it and went back in his cave. Then for about six or seven times, I lifted the mouse up and put it in front of the snake, but he pretended it wasn't even there. So i got rid of that one, too. Then I took him out of his tank the next day and let him rap around my arm. When I put him back in his tank, he landed upside down. Normally he would get up about a half a second later, but this time he didn't even move for about thirty seconds, then he slowly turned over. Most of his life he spends in his cave, (Not just now, this has been forever) fully in. Lately half his body has been hanging out of the cave and he just sits there. I lift that part of his body up and drop it and he doesn't move. but he will stick his head out and look at my hand. I put a mouse in yesterday and he didn't even bother to try to eat it. He just saw it and went back in his cave. Is he dying? Or is he sick or something. Please help!