The best thing for a sore throat etc is a warm salt water gargle.It works for me.
I find that when I am singing but not to excess I get less colds.
If the diaphram is used properly the deep breathing helps to keep the the lungs clear.
A lot of modern popular singers put a lot of strain on the throat.Classical singers learn to avoid this.
Just another tip.Before I perform I will suck a boiled lolly.This seems to clear and relax the throat.
When I was young I had a bout of quinzy and my mum was quick to treat it with salt water.
It came up and was burst within three days.
You go to a doctor and he will give you an antibiotic which takes a fortnight to work.

Hope this helps.

Cousin Ken