When your breath still smells so bad even after you're brushing your teeth daily then it can be caused by bacteria in your mouth or gum disease.
Bad breath smell even after brushing can also be caused by a disease called Periodontitis which is a serious gum disease.
Periodontitis can destroy your jaw bone and damage your gums as well.
If you have bad breath after brushing you can use some apple cider vinegar or Listerine to help keep the bacteria killed off.
But if you do keep having bad breath after brushing I would recommend seeing a dentist because you could have that serious gum infection and disease Periodontitis that can be fixed by a dentist.