Chiropractic adjustment will help. Core Strengthening Exercises- Straight Leg Raised With Toes Turned Outward, repeat 10 times, twice a day. Back Stretching- lie flat, pull one of the knee forward to chest, hold for 3 seconds, then bring the other knee forward to the chest and again hold for 3 seconds. Then pull both knees towards the chest and hold for 3 seconds. Repeat 10 times each exercise twice a day.

At your age most common cause is myofascial pain. Give hot fomentation to the area ,and local.application of analgesic cream.If no relief please consult for muscle relaxants You will.also require proper ergonomic advice

Physiotherapy treatment will help you and stretching exercise of spine and shoulder

Consult with a physiotherapist who have orthopaedic experience. Proper biomechanical assessment and corrective treatment is needed.

U need Physiotherapy sessions for this. So consult to the manual Physiotherapist n do hot water Fomentation. Also follow postural advice

Should meet sports physiotherapust who is expertise in manual therapy

Left shoulder and back pain..It would be great if you could have given pain patten and your occupation. However, i may request you to look into general physician to rule out no cardiac issues by simple ECG. Your back pain and shoulder pain may go away with physio if you are in computer based desk job.