trying to find an answer, normal labs and xrays

How were you diagnosed?

I have had a lump, non painful, in my neck 5 years. 5 years ago I started having soaking sweats to the point of staining sheets because my colored panties who transfew all over my whhite sheets. Saw my internist who did my cbc, xray, and ordered a ct of head and pelvis. The pelvis was denied by insurance. 

5 years later, still weak, not myself, and having tthe clusters of soaking sweats again. Went back, all my lab work came up perfect. Thyroid too. Chest and pelvis xray showed no mass. He wants to refer me back to an oncologist For specific blood tests. I feel like a hypochondriac...trying to find a cause (thyroid, lymphoma, etc)

Did anyone else have a hard time getting diagnosed? Ive heard stories of nodes not showing up on ct or xray and 5 years later they have stage 3 or 4. Should you push for a biopsy? Did anyone get an unexpected diagnosis?