Choking/gasping for air while sleeping

Ive noticed recently that im choking on my saliva while i sleep. I could be just sleeping and all of a sudden wake up not being able to breathe at all. I have to calm myself down to be able to cough my saliva down or out. I hope this makes sense. I would of remembered if something like this has happened to me before but it just started happening this year. Im 23 if that makes a difference. Any one have info or similar experience??