I was just wondering how this was resolved for you, as this seems to be happening to me for the past 2 weeks and I am getting scarred! I am just shy of 26.
Do you lift or work out? Do you have a job that requires lifting or repetitive arm motion?
This sounds like a neck or shoulder injury, a disc out of place or a nerve problem.
I would see your regular doctor and report the symptoms. And obviously if you have any cardiac symptoms like chest pain, shortness of breath or the like, seek an ER. Right now it doesn't sound cardiac, but I'm no doctor...just have experince with lots of nerve problems and have had what you describe. Many, many, many times.