Extreme chest pain help?

i recently had a baby and the day after my gall bladder removed due to gall stones. i had pains that took me to the hospital numerous time cause it was unbearable the doc said it was due to the gall stones so they took my gall bladder but it didn't seem to help the pain i had. i have pains down my sternum and right under the area all the way around to the back it makes it extremley hard to stand up and its like tightening and cramping any ideas? i have tried changing my diet and watching what i eat but to no avail. could it be an ulcer? please help