What Do Sudden Onset Of Neck Pain And Partial Paralysis In My Arm Indicate?

I am a 51 YO female and I have had 2 herniated discs in my neck 4 years ago. At the time I had sudden onset of neck pain and partial paralysis in my arm. It was diagnosed with an MRI, I took a short course of steroids and PT and I was all better in a few months. I had less severe symptoms return a year ago after attempting to water ski. The boat jerked me as I was trying to get up on skis ( I used to be good!) and I knew it hurt my neck again. I didn t go back to the doctor but it gradually got better over a year. Two months ago I slipped on our stairs and as I fell, I caught myself with my arm on the banister. It really strained my arm and hurt pretty bad. Since then I have had weakness and pain in my arm that radiates up my shoulder to my neck. This time it is bothering me when I sleep as many positions seem to bother it and make it worse. It definitely hurts more in certain neck positions laying back or on a pillow. My symptoms are also worse when I wake up. My question is: I know this is caused from that fall and I think it is likely neck related again. However is it possible that it is something entirely different like a rotater cuff problem, and who would be the best person to start with? In short, we have a high deductible insurance plan so I basically pay for all healthcare short of major illness. I want to get to the right person for the least cost. Do I go back to my spine doctor and could they rule out other causes too? Or can you tell me likely cause based on my symptoms?