An orthopedic doctor once said to me:
"People are always asking me, "doc it hurts when I do this. What do I do?"
"Stop doing that," is what I always tell them.
He thought this was hilarious. Mostly because it's true.
This ^^^^
Seriously. Pain & inflammation (swelling is the body's attempt to assist with extra fluid aka lubrication, because something is damaged.) Pain is the body's warning system that something is wrong.
Shoulders are the least stable joint in the body, the equivalent of held together with chewing gum, rubber bands and duct tape. When you lift you are asking non-weight bearing joints to bear weight.....and they honestly aren't designed for that the way your back, hips, knees (and ankles/feet are)....
So weight bearing activities can screw up shoulders quite easily.
Lay off and let it heal.
Also note: Tendons and ligaments (the rubber bands and duct tape), are poorly vascularized, meaning they get little blood supply compared to other tissues. That means they get fewer nutrients (blood brings nutrients) and therefore heal more slowly.
Take the signals your shoulder is sending seriously. Do not push through the pain. Rest & ice first, to reduce inflammation, followed with warm heat to encourage blood flow.
My son ripped his labrum (the menicus like material that lines the cup of the shoulder) and required surgery after 2 dislocations on ROTC obstacle courses (a weight bearing activity where he's hanging from his grip strength, stressing the shoulder)....and his recovery took a year at age 19. He nearly was medically released from ROTC, but he had an excellent surgeon who advocated for him....
My husband's best friend used to lift and lift heavy on a daily basis, ignored nagging pain in his shoulder and ruined both his labrum and his rotator cuff. He had a failed surgery, and has had 3 or 4 other surgeries attempting to fix the initially botched procedure. He's been unable to lift at all for several years now, and it has been debilitating for him (he's 50 something).....and still a mess.
Do not ignore pain & inflammation.
It is the only way your body can signal damage before serious tearing of the joint occurs.