Yes yes yes to dry crackers and jelly babies, they keep your sugar levels up and having something in your stomach helps loads.
Don't worry about what you are eating, though - if you can only eat chips and gravy for a week, then just eat chips and gravy. Keep taking your pregnancy tablets, but baby will be fine anyway.
Drink 'energy' drinks like Lucozade if you can, as they will keep giving you nutrients.
If you are having a day where you can barely keep anything down, even crackers or toast, focus on Lucozade and something like Cupasoup. A doctor told me to do this on really terrible days and it did help, I was actually less sick. I found soups generally pretty good when I was feeling awful.
But above all, keep rested, and keep an eye on how much you are throwing up. There are good anti-nausea drugs available if you are happy to take medication. I was on Stemetil (cyclizine didn't agree with me) from week 8 until the day I gave birth, and it helped keep it in check. If you don't think you are keeping fluids down for a few days, or you start to lose weight, please see your GP. They are much better now about morning sickness/hyperemesis than they used to be.
Hope you start to feel better x