I have a few incredibly amazing things on the burner right now - one thing I haven't mentioned anywhere in public (FB, Twitter, here) and another that I've only hinted at, but if either comes through, it will be a major, life-changing moment. Like... the things that I worry about now would not be the things I worry about after, in large part - they would be replaced by other things that would hopefully be more fun to work on and deal with. Am I being intentionally vague? You know it. Here's the thing - I have learned over the years that it's best to assume that particularly low percentage awesome things will never work out, because when they don't, you're left feeling like the status quo has been maintained. It's not that big a deal. It's a manageable disappointment. However, if you get all worked up and start making serious plans about how you will live your life once everything changes - then it's even more crushing when it doesn't change. The odds don't change whether you're excited or not. You want to keep a cool head.
But within that, you also have to maintain a certain level of optimism, otherwise you'll never get excited enough to do anything at all. It's a tricky balance.
This philosophy originated for me (not that it's all that original anyway - I am sure many other people do this too) after my first novel was politely declined by a set of high-powered editors at New York publishing houses. I had spent years on it, gotten an agent (no easy task at all) and revised the book to the point where it was ready to go out. I was certain I would have a good-sized advance in hand soon, plus a contract for several sequels to the original manuscript. I was going to spend my life doing all I've ever really wanted to do - creating things, telling stories. Six weeks later, after the editors had been given their customary review period, I got a phone call from my agent. He was nice enough about it, but the message didn't change - the editors liked the book, but not enough to buy it. I hung up the phone and stared at my life, not changing in a single miraculous moment, kind of dully staring back at me. It was ugly.
Since then, whenever I've been dealing with something big, I've tried hard not to think about the "after" portion too much, and just focus on increasing my odds of success as much as possible in the "before" portion - after all, that's the 0nly place where I have any control. I keep expectations to a low burn, at best.
It's also helpful, I've found, to, you know, appreciate what you have? My life's pretty phenomenal in many ways. Even if neither of the things I mentioned at the beginning happen, I won't have anything to complain about.