breathing hard

Noticed my fox face is breathing heavy and his gills are a bit bigger than usual but is color is fine. I saw him eating earlier off of the nori but haven’t seen him eat since even after adding food. He does have a spot of ick on him (he’s survived it before and it’s in the tank) I have a qt tank...

So when when I left this morning I fed the tank as normal and everyone ate, there were no issues at all. I come back 2 hours later and I see that my yellow tang is swimming in one spot of the tank but it’s breathing hard and swimming really lethargic (which I don’t know if that would be a word...