People feel and react badly about my breath although i brush 2 times daily

people feel and react badly about how my breath smells although i brush 2 times daily and i am healthy. my family always tell me that my breath does not stink at all. i have visited many doctors and no one identified a cause of bad breath. i sometimes feel poop smell in my nose although no doctor identified what is causing it. wherever i go people start sniff and start staring at me angrily. ANY HELP