I don't want to scare anyone but neck pain that doesn't go away may also be a sign of cancer. But of course, there will probably be other accompanying symptoms like lumps in the throat or swelling. Cancer also causes fatigue and weight loss.
A friend of mine was complaining with a lump in her throat and neck pain. It turned out to be thyroid cancer. She is thankfully fine now. Her thyroid had to be removed and she does have to take medication, synthetic thyroid hormones, for the rest of her life. But she's cancer free and has her health back. It's partly due to early diagnosis.