I shoulder tackled a guy at rugby practice Tuesday night, and did something to my dominate shoulder. I can't lift my hand over my head still, and it has been 2 days. Any movement that causes my arm to move hurts my shoulder. I can't lift my coffee mug or a bottle of water to my mouth to drink. Putting on my shirt in the morning is a 5 minute ordeal. I have to grab my bad arm with my good arm to do simple shit like put my car key in the ignition. I can't even wipe my ass with that arm.
It could be alot of things. Best bet would be getting a referral from your GP and getting that shit MRI-ed. You could also see a PT so they can assess what movements you are having problems with and maybe they could diagnose your injury.
I agree with fufu. Your symptoms are exactly what mine were when I landed on my shoulder while playing softball. After a few days of misery, I went to my GP who referred me to an excellent PT. No surgery required and it took 3 months of PT visits and another 3 months of doing similar stretching exercises at home, but it eventually did heal.
The PT had a model of the shoulder joint. It's one poorly designed joint. As it was explained to me, since there are so many degrees of freedom in the shoulder (think of all the ranges of movement you can do normally), the ligaments and connecting tissues are very "stretchy" (not the technical term, but it escapes me at the moment) and it doesn't take much to mess them up.
i wouldn't try and wait it out. if you can't move it and you are in pain when you try to move it, then you need to get that looked at ASAP. Not moving the shoulder leads to problems in and off itself and not being ABLE to move the shoulder means that something is very wrong. Don't waite.