Lately I have been feeling extremely sluggish, and I have a bad headache with a runny nose and a lot of sneezing. My throat is also sore and I feel weak. Yesterday I small white bump appeared on my upper lip that looked like a pimple. Now today the bump is much bigger and the whole area is red. The area hurts really bad and is tender to the touch. Everyone keeps telling me its a cold sore, but I have never had a cold sore before and I haven't been around anyone that has a cold sore. Can someone please explain what's going on?