Axolotl Might Have Parasites ?

My axolotl, Milk used to be a fine, young, axie, until one day it literally refused every meal i gave. Chopped up earthworms, bloodworms, and pellets. I read that every once in a while, an axolotl might have a hunger strike, so i thought nothing of it. It had some floating problems and it was floating unbalanced near the top, and I didn't know how to fix that either. But recently, its tankmate axie, chips, had died mysteriously. I was scared there was bacteria or bad things in the water, so i did a 50% water change and added some indian almond leaves into the filter. I also fridged Milk for around 2 hours, not leaving it inside for too long because I had to go somewhere and couldn't keep watch. Today, I saw some red things behind Milk's hind legs and I was very worried. Then, after another 50% water change, I found Milk swimming laps at the top of the tank, and sometimes just bumping the sides of the glass. I'm worried it might be parasites.

I have a 30G bare-bottom tank, with a 900L/H filter and 2 airstones (which i put on a timer).