Please help had surgery and i think i have an infection?

I had my gall bladder removed on aug 28 had to spend five days in hospital on antibiotics cause my gall bladder was infected. well now the inside of my belly on hurts and is red before i noticed it had a foul odor so i put peroxide in it hoping that would help and it would not get infected well now its red and hurts and still smells! can i buy anything over counter or should i call my doctor i do not want to go back in the hospital !!! could this be serious!!! what will they do??