So you can't keep down food at all? None?
I agree with the previous posters, talk to your doctor person or go to a new one if you're not taken seriously.
But my other advice (that I've been doing recently) is to eat an amount of food about the size of your fist, once every three waking hours. For women, that's about five of such meals a day. It's supposed to boost metabolism and help build muscle.
If you can't keep down that much food (the size of your fist) at one time, then eat half of that (or as much is sensible for you) for each of those five meals a day. The reason that this should work is that a meal typically takes around two to three hours to digest. I cannot post links yet (due to post count) but it should be easy to find information on this on a search engine like Ask or Google.
I will be praying for you and I hope everything works out