Illness/Sickness: Very sick axolotl

Hello everyone,

I desperately need help on getting my axolotl better!
He's 3years old and has always been happy and healthy.

Few weeks ago I noticed he didn't swim around as much anymore. But I didn't think much of it, since axolotls aren't usually very active. But than he didn't really eat anymore either and I started to panic and got very scared so I went to internet to help me provide with answers, so I learned how to fridge an axolotl and help him recover. So I took the steps in fridging my axolotl. And he has been in the fridge for 2 weeks now. He is very stressed, very weak and does not seem to recover at all. His arms and legs are sometimes under his body and seem like he has no energy.. It really looks like he is dying and I don't know what to do!

Waterlevels in his tank are good, temperature was a little high. He lives on riversand, I recently learned that this is not so good either?

What is good water level? And what is little high temperature?

Pictures?

The fridging could be making him more lethargic too, what temperature is the water when it's in the fridge?
Like DSaxolotl said, attach some pics, your water parameters and temperatures.