Suggest Treatment For Pain In Rib Area Under Armpit

i have this pain in the far left side of my basically in the rib area like from under my arm pit down like five inches and somewhat on my back too but its been going on like this for about four months its a dull pain more annoying than anything and it usually only bothers me when i turn certain ways ibuprofen helps a little but it wont go away what could it be... btw im 22 i weigh around 280 and have high blood pressure the doctor at the clinic said it was muscle spasms butseemed suprised about the length of time