Bad breath

I have bad breath all the time and I don’t know why. I don’t have tonsil stones, I brush my teeth twice a day, I use mouth wash, I scrape my tongue and my breath still stinks of shit. I always chew gum but sometimes it’s not the time and place to. I feel so conscious when I speak to people that I always have to try and lean way from them. Also I’ve been putting off meeting this boy because I don’t want to kiss him and him to smell and taste my bad breath. Please someone help how do you get rid of bad breath?