I used to get bad breath all the time, nowdays, I only get it if my acidity is really bad.
Brushing your teeth works, but you do not want to over do it. If you brush your teeth too much it dries your mouth. so the acid smell which causes bad breath gets even worse with dry mouth. First off you must get the acid under control, once you get that under control, some of the bad breath will go away. Have something to munch on when you have bad breath. Part of it is because acid is seething back in your mouth, so coat your stomach with something.
Experimenting with toothpaste is a key element. In my experience Crest and Ultragel does not work. Colgate with baking soda is good. Strong cheap pepsodent will dry your mouth too much. The best toothpaste is Arm and Hammer Peroxicare with baking soda. It really works. Plus try some orajel, moisturize your tongue.
Hope this works.