Bike Shock 42

Hi...For the past one and a half year I have been commuting 42 km to and fro (office to home) on my pulsar 150 cc (2006 model), but of late for the past 4 months I am experiencing pain in my left shoulder while raising my left arm up. Three to four times I fell off my bike during very low speed without hurting myself. There was a very little bend in shock absorber bars and the workshop guy set it straight and he did some handle bar alignment as well and after that I felt handling is a bit tight and was favoring one side rather than going straight and now my left left shoulder pain is aggravated a bit more unlike in the past. Please help me out.