Abdominal Pain After Lifting Weights

Hi guys… I need an advice
I am 24 yrs old male and I started gymming 5 years ago , when during a workout I got injured… ( hiatal hernia)… doctor didn’t suggested surgery cuz it was not as severe and it took almot a year with medications for me to recover but still there was a constant abdominal pain( mild bearable, kind of a cramp don’t know how to explain but it does not feel good)…there after it took another year and that pain vanished but whenever I lift anything heavy ( say a bucket full of water ) that pain comes back and stays till 2-3 days till I don’t do some stretching… now after 5 years I have again started going to gym … though I am not lifting heavy weightz but the abdominal pain has returned and even after stretching it is not getting well… it’s making me to quit lifting… i dont want to quit … my doctor told me it’s because of weak abdominal muscles. . I don’t know what to do now… plz guide me… ill really appreciate your suggestion