had the flu since last Friday, the temp has gone but the cough isn't going away, keeping me up all night,seems to be worse at night. I feel exhausted. now my gums have stated to be inflamed like I have tooth aches, where I have a plate in my mouth. and now along with the cough the left side of my throat/neck is really sore and seems to be getting worse. is this all from the flu or is there a sinus infection happening as well.