My tongue taste is like "chewing paper". now it is little yellow coloured. i having bad breath. oral thrush?

Maybe thrush(fungus): The tongue is known to have many variations with pigmenting, size, appearance, ; not always due to disease. Causes of tongue that looks patchy include: lichen planus (responds to steroids), white sponge nevus (familial, benign, permanent), smoker's leukoplakia (2% risk of cancer, needs biopsy), hairy leukoplakia (due to epsteinbarr virus), warts (due to papillomavirus), "thrush" (rx antifungals).

Maybe..: Bad breath could be the symptom of several oral conditions. Could very well be thrush, but try to have a thorough cleaning of your mouth including tongue using a tongue scraper rinse with some type of antibiotic (chlorhexidine), etc. If no result, see a dentist to diagnose and prescribe the right medication.