I remember those awful nausea. And for me it was not only morning, it was all day long... For my first one I managed with crackers but for my second one I had to take medication; I was not able to eat at all.
About the possibility of twins, I would say that one of my friends had twins and she was ok. A little nausea but less than me... So maybe it's not the case for you. I really wish you the best! Give us some news when you can!