Upper back pain?

[Ring Shark98]

Last November I injured either my left lat or trap, not exactly sure, when I got darce'd. Pulled the shit out of it, maybe tore it, not sure. Either way I took a lot of time off, but to this day it still feels tender. I'm not worrying about re-injuring it, but it still feels tender and delicate when I roll. When I'm done a good rolling session my upper neck and muscles around my spine are quite sore, but laying down for a while rejuvenates them.

This post may be a bit hard to follow lol, but does anybody have any suggestions or exercise to strengthen the back muscles in that particular area?

Any suggestions would be greatly appreciated. Thanks!