Illness/Sickness: Please I need help I don't know what to do. I can't loose him.

I've had him for over two years but have never seen anything like this.
For two days now he's been red and splotchy and it looks like his skin is bumpy. Like pimples. His tail and gills are curled.
He's not lethargic, he's still moving around, he ate a little last night (salmon pellets). And he passed a poop too but it looked darker and harder than normal.
I did a water test (twice to be sure) and the ammonia was at 0.50 so I did a water change (I do it once a week and it wasn't due until tomorrow but I did it again last night because I'm worried), nitrite is 0 and nitrates are orange on the chart.
Water temps controlled by chiller and are at 63F (double checked with glass thermometer). I've not added anything new to the tank in years or changed any products. The only thing new is a bag of new food bought from the same vendor as always (also a user here).
Please help, idk how to help him. I was thinking bad constipation but I'm worried it's more serious.

He's been super active. Like really doesn't sit still for too long (which is unlike him). and this morning (day three) his gills are now covered in fungus. Please what can I do to make him better, I don't even know what is going on.

My guess is your amonia is too high in the water or it's too hot. You need to get him in fresh water until you can get your tank under control. If your water is too hot then put him in the fridge. There is a sticky under the sick axolotl section that you can see how to do salt baths for fungus. Your baby needs to gain a lot of weight too. If you are fridging him then don't do it for long because he won't eat much in there.

Trip to the fridge and salt bath time!

Here is a fridging guide:

http://www.caudata.org/forum/f46-be...ick-axolotl/85263-axolotl-fridging-guide.html


And here is a salt bath guide:

http://www.caudata.org/forum/f46-be...axolotl/72698-salt-bath-picture-tutorial.html

I hope your little axy gets better soon!!!