What Causes Sore And Painful Lump On Throat?

I have a really sore lump on the left side of my throat. If i press down on it it hurts and when I swallow it is very painful. When i press down on the right side of my throat it is also painful but the pain is not present when I do not touch it. It has been about five days and I am hoping it goes away soon. I do not have any other symptoms. About a year ago I had this same problem and it came back a few times. I feel like this time it is at its worst.