Stop for a moment and think about yourself as a successful writer. Not as a wildly successful writer (doing your Leno interview and trying to decide where to buy the summer home) but rather in terms of what you would consider "success" at all or "success" as a writer.
Achieving success is almost impossible without defining it (as I have written about in an article about Zig Ziglar and success) earlier today. So in order to help you achieve success, sometimes the first step is carefully spelling out for yourself what it actually is. Success can be many different things from a single publication to a published novel to a career that nets 50k a year. It really depends on you because no one else can tell you what success means for you. Just having a definition--just knowing what the target is you want to hit--can help you get there. And articulating all those nebulous dreams into something concrete can both focus and motivate you. (And you may even be surprised at how reasonable achieving a reasonable goal can seem.)
While this may seem facile at first, actually give it a shot. Many people who think it's stupidly easy at first realize that it becomes really hard when they actually start to put it into words. Nebulous "success" is really not a goal we can ever achieve and so we will always struggle against our insatiable hunger.
Write at least one full page identifying what "success" looks like to you. Be as concrete as possible. Use specific numbers and concrete terms as often as you can. (For example, don't just say "pay the bills" but describe whether that means a seedy apartment or a condominium in The Heights. Consider more aspects than just your writing life. What does home life or family success look like. (This can help you figure out where to strike the balance between writing and balance in other parts of your life.) The more specific you can be, the more informative this exercise can become. Be thorough. When you're done check to make sure all your goals are specific and reasonable and think of a way you can measure each of them. ("Critically acclaimed" might be hard to define. "One favorable review in The New York Times" would be much more specific.) Lastly, consider how long you think is reasonable to achieve these goals. Six months might be way too ambitious. Ten years might be way too long. Try to find a good middle ground.
Don't forget that this is just a prompt. So be honest with yourself (getting silly with pipe dreams won't really help) but also...don't forget to have fun.