I am an alcoholic, latley I have been getting this pain and discomfort on the upperside of my left body by the rib cage, what can it be??

Get evaluation. We don't know how long you have had alcoholism, but frequent causes in this group include trauma from falls that are not remembered, nerve pain from malnutrition, early disease onset from impaired immune systems. Ultimately, you need full evaluation by neurology, orthopedics, PMR for pain, and addiction treatment for alcoholism.