I keep getting really sharp pains in my left shoulder. they go up the side of my neck. but if i don't move my arm it doesn't hurt. sometimes it randomly does when i'm laying down. today earlier my trap muscle felt like it was burning while i had the sharp

Muscle spasms: It sounds like your trapezius is spasming or is irritated. That can be sometimes with a simple trigger point injection. You should find a place that will do trigger point injections after they examine you and determine that it is just a spasm.

Left TrapezialStrain: It appears you probably have a left trapezial strain. try moist heat, naproxen or ibuprofen and massage therapy. a cervical pillow may also help. Seek medical attention if pain worsens or weakness develops.