First off...like others have stated...you should get properly diagnosed by a doc, and with an MRI. But, because of your description of pain when throwing, lifting overhead, etc...it does sound like a torn rotator cuff. I had the same issues due to a torn rotator cuff (supraspinatus muscle) that was the result of throwing a heavy rock. Doctor said MRI showed the muscle hanging on by just a couple of strands. He did NOT like the idea of me riding a bike while in that condition because a simple fall (i.e. even a slight crash while riding) and putting my hands out to stop the fall...could very easily result in a complete separation of the already compromised muscle. That would make the surgery to repair it much more difficult...and the already tremendously uncomfortable recovery much worse. Instead of just suturing the muscle securely to your shoulder...the doctor now would have to dig down into your upper arm to pull the muscle back up. Secondly, if it is actually torn, putting off the surgery allows scar tissue to form and that makes proper repair all the more difficult. Good luck.
Dan