Illness/Sickness: Not eating, gills receeded, barely moving

Hi all, I need your expertise please and a little help for my Axolotl. He's a 3 year old black (wild) type and generally is a picture of health. He was a little aggressive with another in the past and so now lives alone and has done for the past year.

I went away for the weekend recently and made sure he was set and ready for a couple of days, fed and a clean tank. When I came home he was floating at the surface with a bulging side so I took this as constipation and quickly got home into a small, shallow cooling tank. After a few hours in there, with small changes to the water and keeping him cool his stomach did receed and he seemed able to lay down again. I slowly matched the waters up and got home back home in his tank but although he isn't floating he has gone down hill.

His head is now quite round (more than usual) and his gills have shrank half of what they were, they were always quite prominent before. He has become very unresponsive and won't eat or move. He does blink every now and again and will occasionally move his front arm slightly.

The water seems OK but I have ordered a new parameter kit and fresh foods. Other than that I am unsure. His tail appears to have a kink in the end but this isn't that new and his black legs are staying back, as if he is swimming. I can get a picture later but I'm at work at the moment.

I'm not sure if he's trying to half way Metamorph as I don't know why he would, I've been against the idea as I don't like the idea of him being in pain and he is cute the way he is, if a little brutish!

Any help to get him eating would be great, his last meal was about 8 days ago now and I'm at a loss.

Hello Doffryn,
Welcome to the forum, and sorry to hear that it is under circumstances where your axolotl is ill.
I cannot answer your question about your axolotl, but I just wanted to respond to you by saying that there are a lot of very experienced axolotl breeders and keepers who are on this forum throughout the day. I am sure that at least one of them will be able to help you.
Hang on in there, someone will be along to offer you some advice.

Upload images from various angles asap,

Thanks for the responses. Sadly I got home from work yesterday to find him no longer with us. His neck appeared to have swollen right out and his eyes were grey and he had died.

I didn't post this last night as I was quite upset and was reading on here of what to do next. He is currently frozen for the period awaiting any pathogens to clear away before burial.

So sorry to hear your sad news.
My thoughts are with you today.