Dizziness 11 weeks pregnant

So for the past 2 days I’ve been really lightheaded I was able to hold cereal down but that was it yesterday so I drank water and tried to eat crackers and I threw that up well today I’m really nauseated and light headed and feel like I’m about to pass out. I go to work in a few hours and I stand for 9 hours without a break... what should I do