Dizziness

So I have been feeling dizzy since Saturday. I think Saturday was going too many hours without eating or drinking. I then called doctor to be safe who said drink 100 ounces of water and eat every three hours. I have been doing that but continue to feel dizzy and shake really bad. Some of it I think becomes anxiety after I get dizzy because I then fear passing out.

She said to stop working out in morning and switch and see if that helps.

Have any of you experienced this and if so what helped?