cant swallow at night and choking

ok this is my first time posting my probs online but im tired of feeling this way.for a while now when i go to bed at night as soon as i lay down it feels like something comes midway up my throat and i cant completely swallow after that unless i sit up for about 20mins. as soon as i sit up i instantly get lots of air coming up and whatever it was is gone.most times i even wake up choking and about to hurl! i hate this feeling cause i have very restless nights because of it. im also getting major heartburn from just about anything i eat. if anyone has any info it would be greatly appreciated. thanks