There can different reasons of pain.
Need proper examination and evaluation of problem.for better treatment plan.
Visit to nearest physiotherapy clinic.
Use pain'relieving gel like volini gel or diclofenac gel.
Use ice pack or hot water fermentation three times a day 10 min-15min.
Start doing exercises for shoulder and neck as well.
Shoulder strengthening exercises and neck isometric exercises.
Trapezius stretch, pectoral stretch.
Need to check with your posture issue as well.
Next Steps
avoid lifting heavy weight.
avoid long sitting.
avoid using high pillow during sleeping.
try to take a break inbetween your work.
Health Tips
for more details information please consult online with physiotherapist with practo app.