If anyone could give me advice of how I might help my betta I'd really appreciate it.
Current water stats:
Ammonia: 0.25 ppm
Nitrates: 10 ppm
Nitrites: 0 ppm
KH: 180 ppm
Backstory: I did a full tank cleaning last night, something I do sparingly but it was time for, made sure to dechlorinate the new water as I usually do with TetraSafe betta water conditioner (I've been using it her entire life), gave it time for the deoxygenization process to go ahead and let the filter run, put Izzy in a small container within the larger tank to adjust to the temperature before letting her loose. Effectively the same process I've gone through every time I've done a full tank cleaning. She seemed fine last night, ate plenty when it was time for her evening feeding, but this morning was very listless, predominantly resting on the bottom of the tank or the niche between her filter and the wall, using short bursts of energy to reach the surface far more often than she usually needs to, gasping for air up there, before drifting back down to the bottom of the tank. I thought it looked like an ammonia or nitrate issue due to the gasping, but the water seems normal after tests and there was no sign of red or brown coloration on her gills (and again, I've been doing the same process for the past two years).
I realize that this may also just be her time, as 2 years old, while far from ancient for a betta, is certainly still a full life. That said, if anyone has any suggestions for what else I might try, I would really appreciate it. In the meantime I'm going to try to go buy an air pump to see if aerating the water might ease her breathing a bit, though she's never had any issue with such before.