Sometimes While Lying Down Sleeping, I Am Awakened Coughing Up

Sometimes while lying down sleeping, I am awakened coughing up saliva and I barely make it to the bathroom. I throw up quiet a bit of saliva( sometimes I make myself throw up as much as I can so I can sleep. This has kept me awake, I sleep in a supine position normally on my left side on 4-6 pillows. Any suggestions I have been diagnosed with acid reflux.