That definitely sounds like a rotator cuff tear. The fact that you cannot sleep is a big indicator. Go to an orthopedic shoulder doctor as soon as you can. I had a complete tear, bicep tear, and labrum tear. It became worse and worse until it was completely torn. The operation is painful but so worth it. 3-4 months of committed physical therapy and my shoulder is 100%. Use a power recliner as for the first week I slept in it. And I rented an ice machine for shoulder for a week helped.