Dizziness in 11th week please help

I woke up this morning feeling TERRIBLE! Worse than I've felt through the whole of my pregnancy, I literally haven't been able to eat at all today so I made a safe option of a couple of slices of toast to put something in me, and I had one bite and was sick immediately in my kitchen sink and my head was spinning so bad I had to sit down on the floor to stop from falling over, was just wondering has this happened to anyone else or should I be worried? :/