With my daughter I had hyperemesis and horrible nausea that lasted all day. I was given a bottle of peppermint oil by a friend of my mother's, and inhaling the vapors REALLY helped to temporarily relieve the symptoms. I also found that smelling an unpeeled orange helped with the nausea.
For the first half of my pregnancy I could not get near my kitchen without getting sick, and I would vomit almost every time I would take my inhalers (I'm asthmatic). I never found anything to calm the vomitting, so ultimately my OB prescribed medication, because I couldn't keep anything down, not even water.
The all day sickness lasted until I was about 14 or 15 weeks. I ended up seeing my OB about every 2 weeks the whole pregnancy, because I didn't gain enough weight and the baby was small. I was induced at 38 weeks and she ended up being 5 lbs and 3 oz.
My daughter is now 3 and we are seeing a fertility specialist to try and have #2. As hard as I found the first pregnancy, I would do it again in a heartbeat!