I second cyclizine. It hasn't quite given me my life back but it has stopped me from vomiting multiple times daily.
I started a thread when I was feeling at death's door asking 'when should you call the doctor about morning sickness' - thank goodness the women on there basically said: CALL THE DOCTOR because next thing I knew I was being admitted to hospital.
If you are dehydrated, too weak to get up, vomiting multiple times a day - I say, call the doctor. Don't let it get to the point you're on an IV just because 'morning sickness is normal.'
Food ideas:
Ice lollies are great for some, or frozen cubes of juice/flat coke, but for me lollies just came straight back up (I didn't try the others)
Crisps were good for me for a while, then peanut butter toast. But I found that after something had worked for a week or so, it stopped working and made me miserable - so back to the experimenting.
Things like cucumber and watermelon have high water content so will help prevent dehydration if you can keep them down.
Good luck, it really was the most miserable time of my life and I still don't feel entirely human at 20 weeks.