@lu1lu2 - Do you have seasonal allergies, or have you recently had a cold, flu, or choking/coughing spell? I used to get that problem when mucus or junk was caught up in my sinuses or tonsils.

If you suspect that might be the origin, you can try washing out your sinuses with a saline-only nasal spray or wash, then thoroughly blowing your nose. And gargling with salt water.

Next, have someone else smell your breath & see if they smell it. If so, you could have a decaying tooth, or an infection in your throat. Another possible cause is a stomach infection known as H. Pylori, which can be diagnosed by your doctor.

Finally, if you had Covid, some people report this as a post-Covid issue.
Do any of these sound possible for you?
Sue