Phlegm or drainage in throat

I am 12 weeks pregnant with twins and have been suffering from excessive drainage in my throat or phlegm. I have tried to cough it up, but usually I end up gagging or throwing up. It never goes away and some foods make it worse. I drink lots of water but have a ton of food aversions. I am still very sick, nauseous all day and vomit several times a day. I was just prescribed an anti-nausea medication but cannot pick it up until tomorrow. Anyone have any remedies for the phlegm?