The past week I've had severe migraines (2x/day) on the left side of my head. I have a swollen lymph node on the same side. What could this be from?

Go see yr Doctor. Any enlarged node, unless caused by a sore throat/infection, needs medical attention. Migraine is probably unrelated to the neck node, yet a medical exam and treatment is necessary and will help you control it and make you feel well if you take a triptan medication which can work wonders to control a migraine.