What Causes Chronic Pain In Neck?

I have been having neck pains for about 3 years. When I lift or carry anything it triggers the pain in my neck. If I am sitting for along time (for ex. At church or at the movies) my neck will be in pain. If I take a hike or long walks my neck is in pain. I am always tired & I just want to rest. My daily life is less active as it use to be.