I'm a writer (for a newspaper), and I agree with all of the posts here--see if you can start out writing for a small or community-based publication, not necessarily for pay, just for experience and exposure. As you will find out clips are so much more valuable than a paycheck when you're looking to move into a writing career!!!
I can identify with the quarter-life crisis thing. I am turning 24 in a few months and have really been thinking a lot about how my life is going and wondering if I'm doing the right thing a lot of the time. I am very happy in my job; that's not the problem. But I'm almost two years out of college and in a lot of ways still live like I'm in college: I party a lot, I bounce from guy to guy and can't seem to find one I like enough to commit to (and vice versa) and I still take financial help from my parents. I have fun. But I wonder a lot lately if I should really just grow up.
Sorry for the tangent, I kind of got off topic!