Rely on Jesus.

In the sport of cricket, a bouncer is a type of delivery, usually bowled by a fast bowler. It is pitched short so that it bounces on the pitch well short of the batsman and rears up to chest or head height (or even higher) as it reaches the batsman. Bouncers are used tactically to drive the batsman back on to his back foot if he has been freely playing front foot scoring shots.
~http://en.wikipedia.org/wiki/Bouncer_(cricket)

Sometimes in life we get into a place where we feel we are just driving at the ball, scoring points and then suddenly life bowls us a bouncer, it's unexpected and drives us back into a defensive position.

Sometimes it's God doing the bowling, maybe we've become too complacent and self-reliant so God serves up a bouncer to bring us back to depending on Him.

Sometimes it's just a result of the broken world we live in.  Not every bad thing, or tough thing, can be blamed on God or His plan to challenge us.  There are times it is our fault, our own sin brings a consequence that bounces up into our faces... but again, other times it is just a result of a sin-filled, broken world.  Disease and sickness can usually not be blamed on anything but the world we live in.  But it can still bounce up at us.

In all cases, though, the answer is the same... rely on God.  Jesus died, He went through some tremendously horrid stuff, but He did it so we can fully rely on Him. When you get bowled a bouncer know that you aren't facing it alone.  Jesus has promised He is with us, and that in the end, or in the light of the most important things we need, "all things work to the good of those who love Him" and "we are more than conquerors" (Romans 8:28 &37)  Even when God is bowling a bouncer you're not the only one handling the bat, Jesus is there too, in you.  You can always rely on Him to help you through anything, even long term, life changing stuff.