I'm sorry you are feeling so horrible Are you taking a pregnancy multi vitamin to make up for your lack of food intake?

I would second what n2l says about grazing, and nuts are an excellent source of protein. Almonds also have loads of calcium so they might be a good choice for you. Crackers with a bit of cheese could work as a small snack and as an alternative to potato chips. Keep trying to introduce new foods and you may find one that agrees with you. I hope this improves for you soon.