What could this be?????

I keep tasting this weird taste for no reason whatsoever, everything tastes like it. I've never tasted this taste before, and I keep smelling this smell that isn't there. No one else smells it, it smells like the thing I keep tasting, and no matter how much I brush my teeth, rinse, gargle, floss etc. I can't get rid of it! Everything I eat tastes like that, and its taking the joy out of eating. What is wrong with me, and what can I do to get rid of this...if anything.