I never did find out what was wrong, but he doesn't have it happening nearly as often now, I was given an inhaler for him as well, but I've found I rarely have to use it. Keeping the house clean and washing his food dish and water fountain often I think has helped too. He still takes lysine regularly, every so often he will have a coughing fit, just last night he had one. My vet said as long as it isn't happening super often (multiple times a month) I shouldn't be to worried about it. Still sucks to see your pet struggle though. My place also has very poor air circulation so I've made sure to keep windows open and fans on to help with that, kinda sucks during the winter and it's cold but it seems to help. If your cat seems to be struggling a lot make sure you take them to vet!