What Causes Headache, Nausea And Sensitivity To Light?

I'm 32 year old female 5'4" 106lb in great health but the past 3 days i have had a headache on the left side of my head, nausea, vomiting, sensitivity to light and just overall "don't feel right." I have been having extremly obscure dreams since this has started. I am currently uninsured and wanted to know is this something i need to go to the er for and what could it possibly be. The pressure on the left side is so severe even to touch my head is painful