part of what helped me is my mother's job working as the business manager for a local hangar and airplane mechanic. hanging around the hangar i saw how many hours went in to maintaining even the smallest two-seat planes. i heard about how many hours pilots logged before they could even look at a small regional jet. the mechanics, pilots, and engineers working on those commercial planes are all the best of the best.
turbulence: when a plane is between 20-40k feet, what feels like a catastrophic drop is, subjectively, not a big deal. sure it's scary and the plane bounces around but the plane will not go down in turbulence. it may drop 10, 20, 50 feet. but you still have 19950 to go before problems arise.
finally, don't psych yourself up reading the manuals about what to do if things go wrong. don't even listen to the presentation. put some headphones on and look out the window at all the people working hard to make sure you and yours arrive at your destination safe and sound.
hope this helped even a little bit. flying is stressful even when you're not scared, but it allows for so much freedom.