Cant get to sleep, i keep coughing?

i keep coughing non stop every time i go to breath in or out i cough, i keep coughing up clear phlegm to. ive tried sleeping in different positions, but i still could not sleep so after 2 hours here i am. im not running a fever, it does not hurt to cough, my throat is not sore, the only thing is i throw up if i cough to hard.my nose keeps running with the same clear phlegm. what should i do? im so tired and just want to sleep but i cant!