Joy I had this on a/c and it was driving me nuts! I recall one day eating a pineapple which tasted to me like an onion..ugh.... I bought a spray called Mouthkote which helped right before a meal, my friend use to freeze cranberry juice in cubes and suck on that before eating.
I don't know if anything like this may work for you but I know it's horrible, I lost a lot of weight just because i could'nt be bothered eating if there was no taste!! Hope it gets better soon