Teething or sick or both? I’m so confused!

Here are his symptoms:

-Low grade fever a few days ago, none since

-Fussiness that’s been improving over past few days. Seems pretty happy today, but still a little extra cuddly than normal

-Obvious swelling where teeth are coming in, but nothing broke through yet

-Dry cough until today, sounds a bit more wet now, but not in his chest. Sounds more like from post nasal drip

-Sneezing with clear, but slightly thicker than water, snot

-always chews on things so I can’t say he’s doing it any more than usual

-waking more at night

I am so confused on how to determine whether this is all from teething or from a an illness. I don’t know how to tell! Any seasoned mama’s want to help me out?