It doesn't sound like thrush but I would have it checked out by an oral surgeon.
maybe your mouth is dry, it's better to keep yourself hydrated. you can chew on sugarless gum or drink water, and keep away from things that can make your mouth dry like smoking and alcohol. just know what causes your bad breath so that you can have a sure-fire way to end it. try http://www.oramd.com/bad-breath-cause.htm , maybe it can help you.
I had a similar problem and my friend recommended this toothepaste to me:
It's an all-natural, toxic-free toothepaste that doesn't contain fluoride. Apparently, fluoride isn't as good for your teeth as people thought, so this dentist developed a better way to protect one's teeth from bacteria. I'd give this a shot though - it's a lot cheaper than going to an oral specialist.