Sounds totally random, but if you can't find lemsip or something like that. Get paracetamol, crush some, put into Mountain Dew then heat in the microwave, tastes the same and has the same effect. I don't know why it works, it just does :)
No point in going to doc IMO. Take some aspirin if it gets really bad, and make sure to eat/drink vitamin C. Press fresh lemons, add hot water and honey. That'll do the trick. But unfortunately it will mainly take time.
The majority of people I know are suffering with this at the moment, some have had it for weeks. Not much you can do but ride it out :( Hope you all feel better soon.