I too get exhausted very easily - but am back to work full time. Isn't it funny how everyone wants you to feel "normal" again so that life can go on? I feel lucky that I didn't have as tough as time as many that I read about on this site.
I had a scare also a couple a weeks ago - I felt a lump on the opposite of the neck. Had an MRI and it bone, not a mass. Talk about feeling like my life was over!! I see the ENT monthly and have seen the RO once since finishing tx, won't see him again until about 6 months out.