I Am A 54 Year Old Male Who Had Triple

I am a 54 year old male who had triple bypass surgery at the end of May. From the moment I woke up after surgery my left shoudler and arm had a great deal of pain. The doctor explained that my left arm was extended over my head behind me to retrieve an artery and in that process may have stretched some muscles but no worries. After about 8-10 weeks the discomfort became less of a daily annoyance but in the mornings it has always been stiff/sore.
Last week I began noticing new sensations in the left pectoral region which had been 99.9% numb since surgery. Sensations ranged from tingling to little lightening bolts of pain. Soon after the left shoulder and arm began to increase in discomfort and over the weekend the same pain as my hours post-op began again. I have complete movement of the shoulder joint but the muscles in my tricep and neck and shoulder connections have waves of pains. My sleep has been greatly disrupted for the past few nights and ironically the most comfort I have is when I lay directly ON the left side and pin the arm and shoulder under me.
I was told my body would be going through some changes for the next year or so. I have modified my diet and exercise routine and can say with confidence I am healthier than I was 25 years ago. Does this sound like a nerve issue and if so is this something that just needs to run it's course?
Any wisdom is welcome and appreciated