well i have always been noticing that people are not getting aware after its injury but i will always prefer icing is the best option to subside your injury and pain too.now as you said being habit it become too difficult for you to adopt with left hand but my suggestion is that u have to compromise till you become all right yeah?and one more advise do exercise go to the gym make your self fit cuz what you are explaining to me is your day to day activity, if your loosing there, its question to your fitness yeah? and as you said u had muscle tear see for the muscle biopsy,mean why you got second episode of muscle tear people who connected with gym activity, athlete they don't have such issue why you only with normal activity?. if it come normal go ahead with what i said to you scapula exercise and give enough rest to your part, and i m not understanding why u want push to steering,cuz pushing activity aggravate your mentioned condition. try to avoid it b little careful saying I NOT TO its not the remedy yeah