I always have this nasty taste in my mouth. It seems like brushing doesn't make it go all the way away, at least not very long, and after I eat it gets really bad. I never used to have the problem like this. What can I do to fix it?
There are several possible causes of the problem of a foul taste or odor in the mouth.
Quite common is dental or gum disease, or tongue conditions --if you have not had a recent dental exam, it is time to do so.
Another possibility is sinusitis with infection in post nasal drainage down the back of the throat causing the taste.
Certain medications, like antibiotics can cause foul tastes that last awhile, and certainly smoking cigarettes or marijuana or any chewing tobacco will do it.
But because of your association with eating, it is most likely acid reflux from the stomach. Start by taking over the counter ranitidine 150 mg twice daily for a week to see if that helps. If not, then try over the counter Prilosec 20 mg daily. If that doesn't make a difference, we need to see you.