On my own dime, I try to find airlines that at least have free booze, it makes it a bit easier. Otherwise, I just suck it up and pay because flights are much better with a few glasses of wine or gin and tonic or vodka and coke.
T, good luck, wash something sleep inducing (for what its worth, last time I took benydryl, the US version, for an allergic reaction, it made me wide awake, so that wouldn't work for me!) down with a few drinks before hand and hopefully you can sleep away!