Well, there's no cure, as I'm sure you know. Take 2 x paracetamol and 2 x ibuprofen every 4 hours and buy one of those vicks nasal sticks that you can keep in your pocket to sniff. Also if you feel THAT bad, it might be worth taking a day off work - you'll probably recover quicker, especially if you work in that type of environment. I know people are wary of taking time off for colds, but you'll have a shorter recovery time and will be more productive once you go back, and you won't spread it to your colleagues.