help! new ball

[kande]

i just got a hold of a ball python hatchling....only im having some problems. Ive owned 2 other balls but they were both over a year old.
ill start off my story.

I got the hatchling form a local breeder at a rep. show. He had many to choose from. I chose the best looking one...and the one that when i handled it seemed the most active and flicked the tounge a lot and didnt seem shy.

He also had a baby mouse (pink with little white hair) in the little container he came in. I had a 20 gal. tank that i could put him in along with some cage accessories and the tank already has an under tank heater attached from a previous snake.
I placed him in after cleaning the cage thoroghly along with the mouse. Well, its been 3 days now and the mouse had recently died and the snake didnt eat it....so i tossed it out. (he actually would curl up with it and keep it warm as if it was his friend)

Well, i went to look at him a little while ago and found him biting himself ?!??? I dont know why he was doing that....So i reached in and got him to stop doing it. I placed him back in the cage after handling him for like 5 minutes and now all he is doing is curling up in a ball and laying in the cage. Im trying to get him used to me so i grabbed him again and decided id let him climb on me while i was at the computer. Only now when i put him in my lap he went back into the ball and suddenly shot his head up as if he wanted to bite me. So i quickly moved and he started biting himself again! And it seems like hes not moving around the cage as much..and when he does it seems like he has little muscle movement....like he cant keep himself up and sometimes lays his head sideways on the floor of his cage as if hes dead. Also, he just had his first stool and it was white with quite a bit of brown fluid....more liquid than solid. All the other ones ive owned were mostly solid with a little fluid....can something be wrong?? should i try feeding him a frozen (but thawed out) pinkie tomorrow??? Im starting to wonder if he really wasnt healthy....or maybe he is just in shock from being in a new home....any help is appreciated!
-Allen