You should rest for a few days, go to bed early take daily vitamins high in vitamin D at least 1,000 IU per serving. A cup of
green tea made very strong (2
tea bags) 2 times a day for 2 days.
Green tea is high in anti oxidants and as a natural anti viral.
If its allergies, be sure to take note of any recent changes around the house. Has some one brought in flowers or recent unpacking of old closets or something unknowingly kicking up dust. What about places you go every other day.