Hello doctor i really need help. i have almost...

Hello doctor i really need help. i have almost tried everything. it has been a year, or a bit more than a year. bad breath is the issue here. i first thought its teeth and oral hygiene: i go to my periodic dentist appointment, and clean my teeth 2-3 or even more. the smell is still there and its very strong. its really embarrassing despite using best mouth wash and cleaning tricks. i can connect the little comfort in my stomach to the smell, i feel i'm in continuous stomach pain but its something i can handle and live with it. but i really need to find a solution for my problem and really quick because its really affecting on my confidence many thanks