Fish is having some problems. Need help.?

Hi, My fish is having some problems. He was doing just fine a couple days ago but yesterday we found him in the morning ledged between a rock (he was literaly sqaushed in there) So I moved the rock so give him some room but he has some problems swimming. First he curves his body into kind of like a "n" looking way where his head is close to his tail. Then he tries so hard with his flippers and his back tail fin to move, but he just stays on the bottom in the same "n" like way moving across the bottom. If he musters up the strength sometimes he can push himself up higher, but it looks like he is having to do alot for that. I feel sorry for this little fish, we just got him and we think he may have been bullied and he either took refuge and did that himself accidentaly, or another fish we have pushed him in there. I beleive it's a problem with his spine due to the way he is swimming. But it looks as if he does NOT want to die, He is hanging on! I put food in there but he haves trouble eating the food, I came back after a day and food still in there. Any help appreciated and SORRY THIS IS LONG!!