In the worst-case scenario, your shoulder pain only gets worse or persists, there’s only one thing left to do; talk to your doctor. Your doctor can professionally examine you and even run some tests to rule anything more serious out.
Once they have a general idea of what’s going on, they can begin to help you. Assuming nothing more sinister is at play, they may prescribe any number of things, including items on this list.
They may even encourage you to seek physical therapy, particularly if the problem is extensive. You may walk out of the office with either some home-remedy advice, or you might have to pick up a prescription for pain medicine.
Some cases of severe muscle strain require steroids in order to relax them and allow them to heal themselves properly. This is a humorously annoying procedure because the steroids are usually injected straight into the upper butt.
Fortunately, you get to choose which side (yay?) but it will still hurt for a while afterward. No one likes getting shots in the butt, so take care of your shoulder.