My son's bad breath is severe. Which hospital should I visit?

My son turned 18 this year.

 

I brush my teeth well in my own way.

I also clean my tongue well with a tongue cleaner.

My bad breath is especially bad ㅠㅠ

 

It seems that other people also notice that I have bad breath.

 

I also feel that my own bad breath is severe.

Even when I brush more thoroughly and clean my tongue carefully,

You seem to be very concerned because of bad breath.

 

Is it because I have bad breath due to feeling unwell?

Or is it because of acid reflux disease causing bad breath?

I just keep overthinking.

 

Which hospital should I go to if I have severe bad breath?

I'm curious if you've had any treatments that were effective for severe bad breath.