You already know what I'm about to say; the only way to know is to see the Doctor. RIGHT NOW.
Without a proper diagnosis, you'll drive yourself crazy and, God forbid if it is a cancer, you'll give it time to do it's work. The faster you have it looked at the faster you'll know for sure.
Take a deep breath. Call the Doctor TODAY. Go and have it checked, and let us all know what you find out. We're here to help.
Cancer is a lot of things; one thing it isn't is an automatic death sentence. Don't give it an inch of ground.
I'm looking forward to hearing that it's nothing to worry about!
Wayne