Severe nausea

I'm so sick to my stomach with this pregnancy it just started tho late at like 12-1/2 weeks im throwing up constantly and can't keep anything down even water. I've been breastfeeding an infant too and im worried there's n9 way i could be hydrated enough but the thought of water makes me puke. How do you all combat severe nausea. With my boy who is now 7 months I had morning sickness from week 4-14 but not at all like this. I rode that through but I was also able to eat here and there.

I'm sick to my stomach all day I'm weak hungry buy having strong food aversions so I cant really eat. I've been munching on pretzels but im still feeling really ill. I'm worried about Zofran and birth defects what can I do?