What Causes Stiffness In Neck?

I have had a stilff neck for about 10 days. It is worse when I turn my head to the left than the right. It is slowing improving and I now have almost full/normal rotation to the right. Shortly after my stiff neck started, I became aware of a "lump in throat" sensation. It feels like it is more on the right side of my throat. I do not have trouble swallowing but I do have constant post-nasal drip. It feels like it is the base of the "Adam's apple" area. I am 60 years old, female, and otherwise healthy.