How do you cope with flying anxiety?

I don’t have a fear of flying. Been an air traveler since I was a kid. But 4 years ago, while waiting for our flight to take-off, the jet suddenly lost power and it became dark and airless inside the aircraft. I hyperventilated and almost passed out! Power came back 30 minutes later after the ground rescue. But it really freaked me out. After that, I became anxious whenever I have to travel by air. Any helpful suggestions?