I found that I couldn't eat whole meals when I had morning sickness. I think that the most important thing is to not let yourself get hungry because hunger makes the sickness feel worse so I would advise to have regular snacks throughout the day, instead of three meals.
Soup also helped me! I couldn't prepare and cook a meal when I felt so ill, so I would have a bowl of soup and this filled me up and soothed the sickness.
Most people say ginger will help, so have ginger biscuits or use ginger when cooking food and it will stop you throwing up. This never worked for me though!
I started to feel better about week 13 on my second pregnancy so hopefully it won't last too long for you.