Severe neck-shoulder-arm pain (r side) (throbbing/pulsating/sharp stabbing). 2 months) X-ray done (normal). Doctor thinks pinched nerve. Relief laying?

Maybe. This one is hard to say without examining your shoulder as it can be hard to distinguish pain arising from shoulder conditions such as impingement or rotator cuff tendonitis from neck conditions such as bulging disc. Need to be examined to truly discern where the problem is from. Xrays can be normal in either condition.
MRI. The combination of neck pain, restricted mobility and arm pain make a herniated disc highly possible. A detailed exam history and an MRI of the neck is diagnostic.