Sounds like you have a muscle spam, I agree with lighter_times, it's something to get checked out. It's less likely to be a simple swollen bursa since you can lift your arm high into the air, it's worth checking out. A walk-in center like Lighter_times suggests is just the kind of place I work in, an urgent care, and these kinds of shoulder symptoms come here all the time.
Dr. Enoch Choi, MD
Palo Alto, CA
Personally I would get it checked out. It could simply be a torn muscle or ligaments. Try some ibuprofen as this is good to reduce any inflammation and ease muscle pain but if the problem gets worse or persists for more than a few days then definately get it checked out by your gp or walk-in centre.