Hi, there are lots of reasons for bad breath. One thing you could consider is tonsiliths, I mention it because I don’t think is is very commonly heard of (well I had never heard of it until I experienced it myself).
Tonsilliths are calicified lumps of food debris that collect in the tonsil cavities at the back of your throat. You may not be aware you have them since they can be concealed inside the tonsil crypt. They can cause bad breath and they absolutley reek! They look white and can vary in size to tiny little specks, the largest I had was slightly smaller than a pea. They can also appear as white gunge.
I feel candida is responsible for mine since I had never experienced them before. Additionally I suffer from post nasil drip which I have noticed on some website can be responsible for their development.
Pressing lightly at the back of the throat can cause them to pop out, if you have a large one then it could take time to come out(I stress very lightly so as not to damage your throat or cause infection). Research on the internet first if anyone is going to try this to get an idea of where abouts and what to expect as I found it quite disturbing when I first tried it.
This is only one cause of bad breath and may not apply to you, there are loads of other causes too.