Taste loss.....frightened..help!

You may have something as simple as a cold - congestion can dull the taste buds.  And one of the symptoms of anaemia is an altered sense of taste.   As iron-deficiencies are a big risk for vegetarians/vegans there may be some mileage in trying to boost the iron and vitamin C content of your diet and, if you don't do so already, take a multivitamin with iron as a back-up.    Foods like fortified breakfast cereals, beans & other pulses (legumes), dark green vegetables (watercress, kale, cabbage), dried apricots, whole eggs, nuts are rich in iron.  Citrus fruit (orange, grapefruit), kiwifruit and berries are rich in Vitamin C.  If you opt to take a supplement wash it down with some orange or cranberry juice so that you can absorb the iron.

If that doesn't help and if the problem carries on for more than a few days then it would make a lot of sense to see your doctor and get checked out. 

Like gi-jane, my first thought is that you might have a cold. If not, I would talk to a doctor. That is weird, my sympathies.