Weird tightness and pain in neck and shoulders

So I don't know if this is something other people experience. I had a cervical injury and pretty much cannot feel anything below the shoulders except some in my biceps.

I was wondering if anyone else had a similar problem though. Sometimes my job randomly starts getting tight. The first few times it happened, I thought I was cold. My jaw was chattering kind of shivering. And then my neck and shoulders would get really tense, and I would try to relax then and relax my jaw, but they kept tensing up. After a while, my neck and shoulders just start hurting really bad. Like if anything touches them at all, they hurt. And they feel really tight. This has happened at somewhat random times, but usually after somebody transfers me from a wheelchair to the bed. I haven't found anything online about it.

I have checked my blood pressure (rather, had somebody check it for me) during these episodes thinking it might be autonomic dysreflexia. But my blood pressure is always normal. Usually it's just annoying and a little painful. But there have been a couple times where the pain got unbearable. Even while taking hydrocodone. Does anyone know what this is? Any guesses?