Sudden lose of appetite/nausea?

Suddenly I have lost my appetite, I get really ravenous like a few times a day, but I eat like 2 bites of whatever it is I chose to eat and I feel nauseous and cant eat anymore. Then the hunger goes away for a few hours. Plus food is loosing its taste, it kinda tastes bland. This has been going on a getting steadily worse for 2 weeks. Occasionally I throw up too, but its always just bile. What is wrong with me?