Dear Kate,
I'm sorry to hear of that you have been ill.Now let me tell you what you should do.
First,you should drink more water.It is good for you to be healthy.Second,you can have a rest and make you comfortable if you have a cold.Third,you had better see a doctor.The doctor can give you some better advice.
But there are also somethings you mustn't do.You shouldn't go to a place with many people.And you had better not make you tired,it isn't good.
So finally,I wish you can be healthy in a short time.
Yours,
Tom