Pain when I eat

I'm 19 days PP, I had my 2nd daughter the beginning of October - via csection, 2nd one I've had; both my daughters were breech - this pregnancy baby was measuring small too.

For some reason every time I eat I have really bad pain in my chest and stomach, to the point I can't eat - ive lost around 1.5 stone since having my daughter this month. I had my gallbladder removed in January due to gallstones so I know its not that. I just wondered if anyone else had experienced this and what was it?