Every time i think of or see food i feel sick, what is going on?

my whole life i loved food, nothing really made me sick, but lately i feel nauseous all the time. the only food i can think about without getting sick is pineapple, bananas, watermelon, oranges, apples, gs. but stuff like meat,veggies, sweets,they all make me sick! i know i should be rejoicing, but i think there is something wrong with me.