In addition to what AHBD said, what are you using to measure your temps?
I read your other thread and saw that just two days ago he was doing well so he's really gone down hill quickly.
In that picture it looks like his head is resting on the rock but his belly isnt? Almost like he's stiffened out from a muscle or neurological issue? Or is it just my eyes deceiving me.
Unfortunately, sometimes babies (especially ones in pet stores) can have ADV, which can cause them serious issues. Unfortunately most babies that actually exhibit symptoms don't actually make it.
So to give your guy the best chance, lets make sure you have a proper
uvb bulb, and that you're measuring your temperatures with a proper tool.
You might have to force feed the little guy to help him out. But, it's unlikely this is from lack of nutrition if he was just eating well two days ago.
-Brandon