it looks to me that you had neck muscles sprain. this can happen when your muscles has to work hard or sudden jerk at your neck. my suggestion to you is that first avoid any sudden movement of neck. apply local heat either warm water bag, moist towel with warm water. you should also take muscle relaxant like myoril or myospaz. Apart from this you can also apply local ointment such as Diclofenec gel. I hope York pain will be better in next two to three days avoid very cold temperature as it tends to prolong stiffness .take care.