Sorry you feel so sick. From my experience this pregnancy (my third) I found a great prenatal that helped my naseau in a matter of three days. It is called vita natal by eclectic institute and their website is eclecticherb.com (you can order throug Azure if you are familiar). It may have been the herbs that are included in the pill like ginger (for digestion) for example. It didn't help my friend in the same way.
I do have a friend that has been as ill as you with all three pregnancies and this pregnancy she took Unisom with good results. Good meaning less throwing up (but still throwing up), more able to function (still sick) but no trips to the hospital this time.
Here is a little info I found re: Unisom. Her midwife suggested it but you would obviously have to decide that you felt ok about using it. She only took one quarter of a pill per day and now (at 5 months along) takes that dose every other day.www.parenting.ivillage.com
had this to say:
Question: I am early in my second pregnancy and am very concerned about morning sickness. During my first pregnancy, I vomited twice a day every day for the full nine months . I have heard wonderful things about Unisom. Is this safe if I end up with never-ending morning sickness again?
Answer: The type of nausea you experienced with your first pregnancy is unlikely to recur with the second although I can understand your concern.
Unisom (doxylamine) is one of the ingredients in Bendectin, which was removed from the market in 1983 amidst speculation that it was implicated in birth defects. The text Drugs in Pregnancy and Lactation by Briggs states:
"The evidence indicating that doxylamine-pyridoxine (Bendectin) is safe in pregnancy is impressive. A number of large studies have discovered no relationship between the drug and birth weight, length, head circumference, gestational age, congenital malformations or other adverse fetal outcomes. Although literature supports the relative safety of this product, when compared to the normal background of malformations, it is not possible to state that it was completely without risk to the fetus."
When a drug is marketed for use in pregnancy, and actually when pregnancy is an indication for use of a drug, researchers must deal with many coincidental birth complications, so it is difficult to rule these out as drug induced.
I would wait to see if you are affected with this type of nausea again so you can make a better risk-benefit determination.