Bloated axolotyl

hi im seriously worried about oscar my axolotyl over the last few weeks he has totaly swollen up and is now only balancing on one leg..

Welcome,
Your axolotl looks awful there's a thread in the sick axolotl bit where someone else's was severely swollen,there may be some useful information there.
Have you been to a vet?

that could be impaction? im not sure, maybe you should fridge him.

In a case like this, you can do some emergency supportive care until you can get advice from a vet. The first thing is to check the parameters of the water as poor water quality can prevent proper osmoregulation by the sick animal. If these are skewed them correcting them can help the affected animal. Ideally, ammonia, and nitrite should be zero and nitrate should be as low as possible.
If the water parameters are in a good place, then you should consider placing it into either isotonic amphibian ringer's solution or a salt solution to help with the fluid retention. See Caudata Culture Articles - Salt Solutions in Treating Salamanders and Caudata Culture Articles: Bloat for suggestions. There are many different causes of fluid retention in amphibians and those need a vet's expertise to diagnose but you can do some of the simple things to make the axolotl more comfortable until you can get medical help.

Ed