feeling of suffocation almost every night, dont know if it's serious.

So about a few months ago i started waking up at night from suffocation, not being able to breathe, chocking and coughing, it continues about 20-30 seconds. When it stops i drink water,(it's hard cuz i continue chocking on it)and then go to sleep. Maybe someone experienced something similar to this? Last time it happened about two days ago i guess.