Well I had morning sickness and lost a total of about 25lbs during my first trimester. well actually I didn't stop being sick at the sight of any food substance until about 16 weeks. Most people say as soon as their first trimester ended, but it was not that simple with me. But i will say that after the first trimester (at about 13 weeks) it started to subsided although i hadn't completely gone away until about 16 weeks. My doctor recommended that I took b6 before meals and to snack on something atleast every two hours, even if it was an apple and crackers to ensure i started holding food down.
I also was referred to a nutritionist/dietician to start to look at food differently and to get other ideas of food to eat that i didnt traditionally eat. I am now 22 weeks pregnant, and I have gained most of the weight back. It has been slow but steady. I can eat almost anything at this point, just a small amount. I still eat about every 2-3 hours, but its mostly fruit and or fresh veggies until meal time. That hold me over and I am never hungry. But i think the b-6 was the key for me to start holding things down.
And I almost forgot, I also learned that I had become lactose intolerant during this pregnancy, so because I was a huge milk drinker before, I continued in early pregnancy, and that contributed to the nausea until i corrected that problem.
And one more thing, to ease my nerves, my doctor told me to make sure I took my prenatal vitamin everyday (preferably at night to ensure I didn't throw it up), and that way, my baby would be getting the essentials that it needed. I hope that my experience helps you. Feel free to send me a message if you would like to talk more. Congrats on your pregnancy and Best of luck to you! :-)
I went through the same thing. I actually lost weight in my first trimester. There are medications your doctor can give you, though mine didn't think it was necessary. The best thing I can suggest is eating frequent, small meals throughout the day. Just try to hang in there and it should ease up a bit when you hit 12 weeks. :)