I felt really awful from week 6 until week 10, when it started to ease off, along with the crippling fatigue. Mine was terrible nausea but by some miracle I've made it to 12 and a half weeks without being sick. Things that helped me:
1. Eat whatever you can muster - ginger nut biscuits, grapes, satsumas, cheese and biscuits etc. Little and often.
2. Drink plenty, especially if you're puking - I survived on cold water with lime cordial as it was really refreshing
3. From the minute I wore my Sea Bands I felt a lot better. A few £ from Boots and they saved my career!
4. Sleep as often as poss for as long as poss. If you're asleep, you can't feel anything!
5. I couldn't sleep at work (obviously) so I discovered the disabled toilet (fortunately we don't have anyone here with any disability that would need it) and would sit in there for 20 mins or so if I was having a bad day. Literally just curled up on the floor. Not glamorous but a little rest helped.
6. Take a pregnancy multivitamin - I take Pregnacare and I really feel a lot better on the days when I do take it than when I forget. It also means that you and the bub are getting what you need whilst your diet's not so hot.
My nausea has been on and off since week 10. This week it seems to have reappeared but I reckon I'm not eating enough, or as regularly, and that's making it worse.