Twisted shoulder about 2 years ago and it still hurts?

About 2 years ago I hurt my shoulder going down my driveway on rollerblades. I ran into my little brothers skateboard ramp and grabbed onto it so I wouldn't fall, but that backfired on me. I grabbed the corner and then fell and twisted my shoulder. I was in a sling for a week and they said to come back within a week if it wasn't better; I didn't. It's been almost 2 years now and it still hurts and its getting worse. Could there possibly be damage or an injury to my shoulder? What kind of damage or injury could I have caused? Thanks!