Oh Pink I feel your fear!!! I hate flying with a passion. I've been doing it but getting worse and more panic stricken with each flight.
I know every single mechanical reason and noise and rational thought as to why it's all perfectly safe but I was still freaking out (internally, only my nearest and dearest ever knew, apparently I looked totally outwardly calm).
I'd tried valium but did nothing for me in fact it made me knackered but didn't stop my mind from working overtime just made me so tired I couldn't move with a racing brain full of fear. I tried hypnotherapy... Pile of poo ime!! 
So this year I saw someone (counsellor who works with airline pilots to deliver courses at airports but I saw her for a private 2 hour session). She taught me a few things that I think have helped (not totally magic wand fixed, but helped).
First thing is, you need to calm your fight or flight response, when you freak out it triggers adrenaline, if you can calm down i
that will be absorbed within 3 mind, if you focus on it more adrenaline is produced it's a vicious cycle. So first thing (3 Ds) is Dispute.... Dispute the thoughts coming in your head, you know they are so unlikely, have some are flying stats etc at hand instead. Not too much detail but enough to dispute the fearful thought.
Then its Destress... Not the easiest if travelling with small children but if you can get meditation, relaxing music, relaxation tape and focus on breathing calmly, happy scenarios.
Then when you are calmer, Distract, keep your mind off it. It needs to be something that will engage your brain eg reading provably won't cut it, sudoku might, something with your DC's might but it needs to stimulate you not just physically occupy.
Then repeat the 3Ds as required in whatever order throughout the flight.
Sorry to ramble but as I say it didn't fix me but it did substantially help. PM me if you want more details or to talk through.
Good luck, it's hateful to go through and apologies in advance for numerous typos on my stupid backup phone (main one bust)