Rotator cuff surgery.

After I swam for a month in Oct. in pain,I had an X-ray and then MRI to show that I have a partially torn rotator cuff. Doc says it "should heal by itself, given time" How long an my age of almost 75 will this take and no guarantee to a positive result is unknown to me. Have any of had this type of surgery done and what are your results? How long is recovery? What do think of the repair after going back to swimming? I have been pretty good at IM and fly. Will I be able to recovery enough to continue these strokes? Thanx to all that offer advice.