hi, as you mentioned about the disc injuries, this is a classical symptoms that the nerve is getting trapped in the cervical spine and if possible an MRI can be done to come closer to diagnosis. also the reason for the pain is early fatigue occuring in the muscles. Fatigue is occurred by the reduced metabolism and in a lamen sentence as low endurance. To regain the active functional life you need to focus on performing static neck exercises , pushups and later on upper limb strengthening exercises. Also breathing exercises are a must to provide good oxygen to lungs and also to strenthen the accessory muscles of respiration which will inturn strengthen the muscles which supports the age. also when ageing of the spine starts small symptoms come and the muscle Strengthening plays a key role to put a hold onto the ageing. Also at a later stage you should strengthen the core and spinal muscles to keep the spine stronger. everyday exercise keeps the body to the optimum good health. I have seen many cases and at about few weeks of time the symptoms are totally eradicated and the body is strong enough again. with the grace of God I wish you a speedy recovery regards