Illness/Sickness: Nitrate burns?

HELP!!!

The night before last I had moved my two axolotls into a newly cycled tank. I performed about a 65% water change, but in a ll the excitemnet, I forgot to test the nitrates after the water change to make sure they werent too high. Well they were, lile 80 ppm. But I didnt realize till the next morning when they were acting really strange and I tested the water (yes, I used liquid test kit not strips).

My axies were very spiratic and their gils were burned/singed. Im assuming from the nitrates because ammonia and nitrite were both still 0.
I did another water change to lower the nitrates. I did too mich of a water change and now nitrates are also 0. Is thay bad? Did I just ruin the cycle? What do i do now? Both of my axies have since calmed, but their gills are in pretty poor shape. What do I do to help that? I was thinking I could do either a tea bath, or I have catappa/indian almond leaves I could put in the water.

Yesterday, both axies were uninterested in food, the day I found out the nitrates were high and did a water change. I will try again today.

Other info:
I ised API water conditioner. Just plain water conditioner, not with aloe or anything.
They are both moving around very slowly and very little, their gills are pale.
Theure both isually very interactive and energetic.
Water temp is about 62 degrees F
I have fine sand substrate, silica based
My younger axie has been siting with his mouth open (I know some do this, but he never has, its not gaping but open enough that I can see inside)
The younger one did eat a small worm yesterday (much smaller than what I usually give so O dont think thats why his mouth is open) the older one didnt eat at all.
I have external canister filter, there is no water movement at the bottom, I have filter floss over the input and output has a spraybar.
Theyre in a pretty dark area so light isnt a big stressor.
Not eating, singed gills, but rest of body and skin looks normal. (By burned I mean, they look like when you burn barbie doll hairs. Theyre much shorter, thinner, pale, and they look “chunky” instead of flowy. Im sure some know what Im talking about)

Please give any advice you can. Shold l I remove them from the tank even though Ive brought the nitrates back down? Did I crash the cycle? Should I be worried that theure still pretty inactive, or is it just them recovering? How long should I let them adjust before I should be worried about their behavior?

Forgive the typos, this site isnt super mobile friendly.

I think you should tub them asap, there is something going on with your water.
It is possible that adding them all the the tank at the same tine has stressed the bio load, and it needs to catch up.
So tub them for a few days and monitor your parameters, make sure the cycle is stable and not crashed, then add one at a time per day.
Hope this helps!

Oops, I forgot to add, using Indian Almond Leaves while they’re tubbed is a good idea, and yes tea baths can also help.

Ive had both of my axies tubbed and in the fridge to treat fungus for about a week now. And Ive noticed that when I used seachem prime, they are just fine. But when I use API Tap water conditioner, they freal out and are acting weird, like gagging and whipping around. So now I know I cant use API with them. Idk what it is, maybe theyre just so used to the seachem cuz Ive always used it. But now comes the problem of, how do I treat the tank? When I treated the tank I ised API. So when I do water changes, is it ok to start using seachem to treat the new water I put in? Even though the tank was originally treated with API? Will switching conditioners cause issues??

I don't think switching conditioners will cause any problems