A bit like how the song helped, if you now start to replace any negative thoughts about your upcoming flight with 'it will be ok, everything will be fine', this will give you something tangible to think about, rather than trying not to think about all the terrifying scenarios you're probably very good at coming up with! It's also the truth, where your negative thoughts are exaggerations and are untrue. Even if things don't go perfectly, they will work out in the end and everything will be ok.
Good luck!