There are two components to your condition.
Cervical Disc Problem which might be hitting one of the upper arm nerve which causes radiating pain down your arm.
Second is supraspinatous tendinosis. Which presents with pain only in the shoulder with restriction of overhead movement.
To confirm the diagnosis in person assesment is needed.
Next Steps
To consult a spine specialist near you.
Health Tips
1. Use USI brace for shoulder for 1-2 weeks and see the results, if your shoulder pain is decreasing then continue it for one more week and then start physiotherapy.
2. For neck, start with posture modifications which include keeping your eyesight parallel to screen while working, avoiding using mobile in forward bended position and physiotherapy to strenghten you neck muscles.