Severe nausea and vomiting

So I am pregnant with twins and have been so horribly sick since 5 weeks I'm currently 9 weeks. I have seen my Dr 2 times she first put me on zofran which helped for a few days then stopped, then diclegis which only helped for a few days and I'm still sick. What else can I do? I have never been this sick with my past pregnancies its insane. And I've tried everything in the book.