Throwing Up

LO is spitting up huge amounts and dry heaving. She doesn't have a fever and isn't really acting sick, but her dry heaving is scaring me and the amount she has thrown up is concerning. I can't get ahold of any doctors or nurses to talk to at the moment. I'm worried she is going to choke on her vomit if I put her to sleep on her back. I'm also worried she isn't getting enough nutrients since she is throwing everything up but don't know what I can give her as she is only 11 weeks. Does anyone have experience with this?