Yesterday morning I woke to find a painful round raised lump on the roof of my mouth on the left side near my gum. Throughout the day it kept swelling and became increasingly painful. Last night it was the size of a dime. I took some Ibuprofen and tried to sleep. Kept sweating and then being cold. When I woke this morning the lump was gone as well as the pain, and when I looked in my mouth I saw what appeared to be a pimple that had burst on it's own. This has never happened before and the only info I can find seems to be about smaller mouth sores. This one was substantial and went as fast as it came. I use mouthwash and brush well. Any idea what on earth caused this? I'm in my 40s. I did suffer from acne when I was young but have not had any breakouts in years. Any input is appreciated. Thanks.