My first thought is stress or a panic attack. My 2nd thought would be sleep apnea (you actually stop breathing while you are asleep decreasing oxygen to the brain and decreasing circulation) Both are very much treatable so don't worry. You need to see a doctor though. He may order a sleep study which just means spending a night at the hospital hooked up to a bunch of monitors, it's not a hospital admission, more like staying at a friends for the night.
If it is apnea you will have other symptoms: snoring, always tired, yawning, trouble focusing, falling asleep during the day.
I have this same problem...I haven't seen a doctor for it, but I will suggest you just assume it is hallucination.
You may actually not be asleep, but your mind may be...or you're just hallucinating.
Good luck ♥
I would tell your parents to make you a drs appt to discuss this matter.