“Bad breath?”

Periodontal disease, gum disease, typically causes bad breath but so does stomach problems. If it's only gum disease you need to get a deep scaling and root planning to get the gum disease under control. You should never be brushing your teeth in a way that would cause the recession of your gums. In any event, you need to get to a dentist and get an evaluation of your periodontal health and get it treated and you'll get the bad breath eliminated. Plus, before and after you visit the dentist you need to start flossing everyday. Remember this joke, you only need to floss those you want to keep everyday. Thankfully , your problem should be fixable.

Bad breath sometimes is due to a specific culture of bacteria which cause an advanced for mf gum disease called periodontitis. That type of gum disease is only manageable by a dentist. Your dentist can clean inside the deep pockets around your teeth that are not possible to clean by brushing only.

There are a few sources for bad breath. I recommend you see a dentist for evaluation.

There can be underlying health issue that can be causing it. You should find a dentist to see if they can diagnosis the reason.

This is a frequent concern.
Breath odors can come from sources such as:
tonsils, lungs, sinus, bacteria below the gum, system wide disorders, imagined, others.
A very common problem is unseen bacteria beneath the gum. A history of limited cleaning between the teeth, and lack of professional cleanings can allow this problem.
The best solution would be a visit with your dentist to confirm or rule out this possibility. With this answer you can move forward with treatment for it, or search one of the above mentioned possibilities.
For the best information about how to clean 360 Degrees around each tooth, for every age, or medical condition, study the book:
GROWING A HEALTHY CHILD, SECRETS FROM A WISE OLD DOC.
Thank you for your excellent question.