D.W.
I'd be really diligent in working with your doctor. Your symptoms are really common, so it could be so many things.
When my daughter was 7 weeks old, I found a small, swollen lymph node. My OB/GYN wasn't concerned so I went to my Family Physician who thought it was worth checking out. I got a breast ultrasound (since I was postpartum), and the radiologist thought the node looked benign. My white counts were normal, but my C Reactive Proteins were slightly elevated. Really no reason for concern.
I was fatigued and losing weight, but what breast feeding Mom isn't.
So, I won't want to scare you....it's really important for me to say that. But, my diagnosis came back as stage 2A Hodgkins Lymphoma (cancer). I had NO symptoms that would have led anyone to think that other than that 1 swollen node that made my instincts kick into high gear.
Document all your interactions with your physician so you have proof for your employer that you've been proactive in dealing with it. If it is viral, you'll just have to let your body run its course.
If your gut is telling you to keep getting resolution, don't stop listening to it.
I hope you are well soon.
Good luck!