I Have Had Shoulder Pain For 2 Weeks. In A

I have had shoulder pain for 2 weeks. In a resting position It feels pretty deep in the muscle like an ache from a flu shot. I have difficulty moving my arm in certain directions because I get sharp pains, mostly attempting to straighten it horizontal and then in an upward motion. Last night I noticed that I have red lines like broken blood capillaries on the top of my shoulder. It hasn't gotten any better and my doctor thinks I may of strained a muscle. I'm a little concerned as it is very painful to sleep at night on either side. Is it possible I may of torn a muscle?