What is this caused from?

Sometimes I'll wake up in the night gasping for air. I tried to breathe in and can't very good then I cough and cough it takes a couple minutes to clear away, it's so scary. Back when I smoked weed I thought maybe it was just a spasm, now i don't smoke and still do it occasionally. Then I wondered if it was saliva going down my lungs when I snore. I've been told I snore really bad. And yes, someday I'm going to the doctor to be seen for all kinds of different stuff so I don't need to be told that. I just want to know what it is, or if it is a symptom of sleep apnea