Swollen Lymph Nodes

the night before New years eve, my mom had a swollen left side of her face which starting under her ear down to her neck. The swelling was rigid and not painful.Checking her tonsils, the left tonsil had been pushed till the mid of her mouth and was quite red. The dr advised to have an echo to decide what kind of swelling it is, founf to be swelling lymph nodes with an enlarged thyroid. He sent us for biopsy, by the time of biopsy, the swelling has shrank to a great extent but was still there, left tonsil still not in place.The dr of biposy advised not to do a biopsy and wait for sometime,and asked for blood tests.all were normal,including the thyroid hormones that were all in range.after two weeks we visited him and the swelling has reduced further yet the left tonsil was not yet back to normal.now he asked for a CT scan to see why is the thyroid is that enlarged. while asked, mom revealed to have no symptoms whatsoever(hardness in breathing or hardness in swallowing,etc...)Tomorrow is the CT scan, today the swelling has moved to the right side. I'm terribly scared and can't get myself to sleep, could it be dangerous?cancer? please advise..