16 weeks pregnant and need help?

This is my third pregnancy and this one seems so different from the last two. Anyways I woke up thi morning with what I thought was just morning sickness. But now Im not to sure. I have a prescription for morning sickness which I want to take but I can't even keep down a sip of water. I have lost 3 pounds by throwing up today. I have tried crackers, bread, ginger cookies all the stuff they tell you. But is there anything else I can do?