Uneven deformed rib cage. Better health.

I can feel left side rib cage is having sharp curve around nipple and flat or pressed at back side. Left side Rib cage is coming out more as compare to right side, around navel.  Whenever I try to do exercise, do yoga, pranayam, go to gym or do any other physical activity o start feeling pain around back side of left armpits in rib cage. Also feel heavy head left side. I feel after doing any exercise it gets more deformed and starts paining. This stops me doing any kind of exercise or pranayam for better health. While doing gym I tried very hard to balance both my hand and shoulder so as to put equal wait but still pain increases and rib cage feels more deformed. By birth I was left handed but then parents forced me to be right handed as per Indian values. When I play any sport where I don't focus on putting equal pressure then this pain doesn't increase. Please suggest what is to be done to get rid of this issue so that I can be more physically active for better health.