Help with baby Red Eared Slider!!!?

Ok, so my baby Red Eared Slider was a little sick when I got it. The bottom of his shell, is soft and squishy and not hard like my other babies. He also CONSTANTLY has his eyes closed all the time! He will sit at the bottom of the tank with his eyes closed! Only sometimes will he open his eyes under the light. I dont want to buy a new one, because I don't want to give up on this little guy. So, I have the sick little guy, Herbert, on a floating dock raft thing, with a nice uvb/heat light over him. I don't really know what else to do! He won't even eat because his eyes are always closed! Please someone help me before he just dies!