Quite some pain in the neck/shoulder region [25m]

Since about four hours ago I've started to notice that my shoulder region is starting to hurt a lot. The pain starts from the upper spine / lower neck and radiates out into my left arm. I can feel it hurting when I look to the right. When I try to sit up straight when I am laying down, the same spot radiates out pain.

It feels as if I have severely pulled a muscle. Quite fortunate some stretching has made it feel better for now.

At this rate I may call my chiropractor, since it feels like it stems from between the spine and the shoulder. Anything I can do to make it hurt less in the meanwhile? (at least a solid 9 hours before I can call)