To tell you the truth, I'm not sure what's going on.
Though, I did read a topic on this forum that sounded a bit like my problem.
I didnt eat dinner one day because I felt terribly sick, then that night I woke up, feeling extremely nauseous.
I stayed up all night waiting to vomit, but it never happened.
The next day, I didnt eat breakfast or lunch just because I wasnt all that hungry.
For dinner I ate chicken noodle soup; I seemed to digest that pretty well.
That night I didnt seem sick.
So, today, I didnt eat breakfast...but I ate lunch, which was just apple sauce for fear of bringing up that uncomfortable nauseous feeling again.
Not too long ago, I tried to eat real food, but, I barely got any food down when I started to feel nauseous again...and very tired.

Ever since that one night where I couldnt eat dinner, I've been feeling VERY tired and dizzy...plus weak.
My hands are constantly shaking.
I really dont know what's wrong since my illnesses/nausea usually last a day.
My mother said it could be depression or anxiety since I have an anxiety disorder.
But I really dont think it's that at all.