How to i stop the pain in my neck?

My neck has been stiff and in pain for quite a long time, and its really starting to get on my nerves. Every- time i work out or just walk, my neck gets stiff and i mean extreamly stiff, then i start feeling pain around my neck, i then stop working out or walking for a while to try stretching my neck to relieve the pain, and nothing works, someone please help.