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 felt like this in morning after working out.

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