Suggest Remedy For Pain In Underarm And Around The Chest Area

Question : Last night I started having pain in my underarm, around the area where my underarm and chest come together. It's a sharp pain that leaves my arm pit tender to the touch. I've never felt this before. Since I still had the pain this morning, I took Tylenol but that didn't do much. A few days ago I had a reoccurring pain return which is a sharp pain on the right side of my head a few inches above my ear. This also leaves my head feeling tender to the touch in that spot, it feels as if I'm being shocked. My neurologist doesn't have any availability for a few weeks. I took the Gabapentin that he gave me for leg pain (same "shock" type pain) and it seemed to help the head pains ( have not tried it yet for the arm pit pain). I have no lifted anything heavy recently or over exerted myself. Do you think this is all related and what could it be? It is completely different areas of the body, but it's strange that i'm getting the same pain all over the place. The head pain is becoming debilitating and I'm realizing that it's not just a migraine or sinus issue so I'm finally looking into it. Thank You!