Over the past two days I have noticed a large uncomfortable swelling behind my right ear. But further towards the middle of the back of my head and on the hair line. It's painful to touch, and even looking to my right is uncomfortable, it feels slightly hot but not when I touch it? It actually feels like when your knock or bump and existing bruise, that kind of dull ache. It's fairly big, maybe the size of a two pence piece, I has no head, I've been using painkillers for another reason but this still gives me pain. It's the area of the head and neck where the occipital nodes are, and I'm a little worried.
any clues on what this could be?