Upper lats injured

Squatting 305 pounds at the gym and it was the last set, so when i went under the bar to get it off the rack and onto my shoulders, and i felt a pain in my upper lats.
After i finished the set, I felt more pain in my upper lats when i tried trunk rotations. So now whenever I move my trunk, like twist a bit, it hurts. Its on the right side. It gives a deep type of pain thats really annoying too. I can run without it hurting and still do a lot of lifts, but whenver I move twist my trunk a bit it hurts.

Any ideas? treatments?