I pulled the pectoral muscle a year ago.did some therapy for it and accupuncture,been on all kinds of meds.Nothing helped

Recently i started getting this really shooting,sharpp pain in my left breast,arm and my shoulder.I went and saw an orthopedic doctor,did an mri,everything is fine.He cant figure out whats wrong.told me to go do therapy again for 4 weeks and put me on some meds.
I cant stand this pain.It feels like someone is stabbing me and my arm goes numb.And its nothing related to a heart attack or anything
HAs anyone had this pain from a pulled muscle?