Help with my Axolotl

Hey all, not really a place I would post but I can't figure out anything for the life of me. My axolotl I have had for around 2-3 years, it's a female, and I believe it's got Mexican Origins (however please do not quote me on this)

A few days ago we noticed the water had gotten bad a lot faster than usual, we did a 50% water change whilst adjusting the parameters of the water to a safe level, the axolotl however soon became rather stressed or fell victim to chemical or water shock. She started to just float with a slightly bent tip in the tail, little gill movement, and slightly ajar mouth, we decided to move her to a small bowl to see if she could improve, she eventually did but however soon fell victim to this again, we then decided to replace the bowl water and allow her to sit, this happened again last night and I went to bed having seen signs of life last night with her gills and a bit of movement.

But now she has done it again, I'm really not sure why, I'm not sure what I'm supposed to do. I've replaced the water, however I discovered the thermometer she had in her tank was broken and full of water, I quickly realised it had a big hole in the top where the glass had broke, this could be from when I inspected it however I am not sure. I've moved her to the side of my bed where she is in as dark as a place as I can get and quiet. Her tank does have a filter and the parameters are normal. We're not sure why this has happened.

She floats on the surface at a small angle, her top of her head (not face) is slightly above the water, her toes bounce as she makes contact with the floor, her mouth is slightly open.

Any help is greatly appreciated.