I'm 7 weeks today and the past 4 days I've had no appetite and feel so sick if I eat anything, but also feel sick if I don't!

I'll feel so lethargic and no energy and I know I need to eat but the thought of any type of food makes my stomach turn and if I do cave in and eat something I do feel better immediately! but then I get the worst upset stomach and everything I ate goes right through me and I pay for it for hours.

Anyone else experiencing this or have any tips on how to deal with it?