2 Nights Ago I Very Suddenly Felt A Pulling Sensation

2 nights ago I very suddenly felt a pulling sensation in the back of my neck and upper shoulder area. The intensity of the pain was not so bad during the day but it quite bad at night. Today I have heaviness in the back of my neck and base of my head and I have a headache that no medicine is alleviating. I don't recall sleeping in a bad position.