inflammed lymph node

[Maria Elizabeth]

Hi, this is the second time in about six months that I have been awakened from a sound sleep by a very hard swollen area right behind the right jawbone that I didn't have before I went to sleep. When I place the four fingers of my hand in a vertical position right below my ear lobe and press it's very tender there. The last time this happened it was more painful and interfered with my swallowing. I saw a doctor and was told it was either dental in origin or a swollen lymph node. The dental origin was ruled out and I was prescribed an antibiotic (of course). The hardness and discomfort is more bothersome when I'm lying down. I've been up for several hours now during which time the hardness has practically gone and the swelling has lessened but it's still very tender and tight particularly closer to the jawbone. How can I treat this, and, more importantly, what is the underlying cause that I need to address?

In gratitude for whatever help I can get.

Maria Elizabeth