I guess all you have to do is wait for sometime before it gets reverted back to the sender address. Do not loose your private key. And do not transfer such a big amount in one go. Split them if you may, also, do not send them to a single BTC address, generate multiple addresses so not all coins are in one location.
yeah, private key is damn important, don't lose it, you may tell someone you trust or put it somewhere only you can find, Don't put all coins in just one location.