Your description of pain is noncardiac as your ECG it is OK. Therere is pain in shoulder and neck muscles so it sholud be from cervical spine
. Please consult a Orthopedic surgeon and get your crvical spine X ray
AP and lateral view and if required MRI of spine, once diagnosis is confirmed it may be treated with analgesic
and muscle relaxants and local physiotherapy
may be SWD or local ultrasound
will give relief and neck muscles exercises after you pain improves.
Later on you can do a TMT to rule out any cardiac problem if there is any doubt.
Good luck to you.