I have Lymph Nodes where? or When do I get to stop worrying?

After months of increasingly bad and even more so increasingly frequent headaches that have turned into migraines, and after finding a lump on the side of my head I probably should have had looked at right away, I went in to see my doctor today. He's pretty sure the lump is a cyst. What kind you ask? One to do with the lymphs in that area of my head apparently.

He's also pretty sure it's benign, and probably unrelated to my headaches. I'm hoping that's not just the kind of line you tell someone when it worries you that they might be related and you just don't want to scare them.

In any case, doctor's orders I'm heading in for an MRI tomorrow at 4pm. I'm trying not to be scared, but the fact that I'm also dealing with some depression issues right now makes that pretty well tough to manage. Every time I think "don't be scared" I get scared and I start crying.

If they don't find anything in the MRI that IS causing these headaches, then what? Do I just live with this? How much worse can they get before they become altogether debilitating?