Bad breath problem... doctors pls help ........!?

I have bad breath problem since 10 years which is very embring to me. i met so many doctors but there is no solution. recently i went to appolo hospital they told me that it might be either with my backside of toungue(yelloyish) OR tonsils which are might be infected. Dr. told me to clean my backside toungue with tooth brush which i tried since 6 months- no results. now i want to go for tonsils operation. pls give me suggetion.....any doctors pls....