Get checked for stomach ulcers as well. Stomach issues can cause bad breath.
Do you have/use a tongue scrubber or tongue scraper? Bad smells come from bacteria on the tongue (the white stuff). Try Therabreath brand mouth wash, dentist recommended it to my fiance who was having similar issues. He started using a tongue gel and tongue scraper ans the mouthwash after brushing his teeth and it's helped temendously.