I was in the middle of interviewing a guy at work when I suddenly felt the color drain from my face. A thought had popped into my mind — "Today is my half birthday." I, thankfully, had my tape recorder running because I zoned out for a few minutes as I repeated this singular thought over and over in my mind.

I know that most people probably stop caring about their half birthday after the age of, like, 10. But this year is different. I freaked out because, as of today, I am 29 and a half. Which means I only have six months left in my 20s.

I told my boyfriend, "I thought I would've done more by the time I was 30. Like get married, buy a house, get a book published, be a millionaire...the important stuff."

But the truth is, none of that is what is actually making me anxious. I'm actually completely content right now not being married and living by myself. And I enjoy living in an apartment. I like being able to call maintenance whenever there's a problem instead of having to fix it myself. And I like having the option that, if ever I wanted to pick up and move, I could.

Sure, I want these things someday - to get married, have a house, and, maybe, have kids (the verdict is still out for that one). But there shouldn't be a timeline. Maybe you were married with a house by the time you were 21. Or maybe this didn't happen for you until your 50s. Or maybe you decided you never wanted to get married. As long as you're happy, who cares?!

That's why what I've accomplished or haven't accomplished in my 20s (although publishing a book and becoming a millionaire would've been nice) isn't what makes me anxious about turning 30.

I apologize in advance; I know everyone over 30 is going to roll your eyes at me for freaking out about this. But the thing that makes me anxious is something that's completely out of my control — aging.

A woman at work recently celebrated her 50th birthday, and, as a joke, we (her coworkers) decorated her cubical with "29th birthday" decorations. But, as I was helping hang up the decorations, I had a very selfish thought: "Oh my god! I'm at the last age when people aren't ashamed of their age!"

But the thing is, it's not really "the last age when people aren't ashamed of their age." It's "the last age when women aren't ashamed of their age." Because, yeah, aging is a lot harder for women. And (try not to read this in a whiny voice) but...it's not fair!

I am constantly reminded of my age whenever the fact that my boyfriend is four years younger than me is brought up. We will joke about it with our friends. But the thing is — why is it funny when, if it was the other way around and my boyfriend was four years older than me, no one would even blink?

Because, even though women, on average, live longer than men, youthfulness is epitomized in women. It's why I have heard people joke, "Oh, that guy only dates women in their 20s"... even though he, himself, isn't in his 20s. It's why actor John Stamos can announce that he's engaged to marry someone 23 years his junior (the same age as the Olsen twins)...yet you hardly ever hear of a female celeb doing the same. It's why, two years ago, actress Maggie Gyllenhall was told that she was "too old," at age 37, to play the love interest of a 55-year-old man. And, it's why I nearly broke down crying when I found my first grey hair, even though men can show off their salt-and-pepper hair with pride. 

Deep down, I know that I'm not old. I can still party with my 23-year-old friends and date my 25-year-old boyfriend without feeling like there's a neon sign hanging above my head that says, "She's almost 30." My parents have always told me, "Age is just a number. What matters is how old you feel." So, why can't I stop panicking about it? Why does it feel more than just the end of a decade but like it's the end of something else as well?

Because as author Ashton Applewhite wrote in a column for the New York Times, "(Women) bear the brunt of the equation of beauty with youth and youth with power — the double-whammy of ageism and sexism."

I know she probably didn't write the article for women in their late 20's or 30's. Yet I still related to it. And that sucks that, at age 29, I'm already scared of aging. But Ashton said that being scared of aging or pretending you are younger than you are is "rooted in shame over something that shouldn’t be shameful. And they give a pass to the underlying discrimination that makes them necessary."

She challenges women to move from denying aging to accepting and embracing it.

"Prejudices pit us against one another, like moms who work outside the home arguing with stay-at-home moms about who’s a better parent, instead of joining forces to close the wage gap," she wrote.

"We can move, if we have the will and the desire and the vision, from competing to collaborating. ... The women’s movement taught us to claim our power; a pro-aging movement will teach us to hold onto it."

I'm working on it, Ashton. I'm working on it. I vow to never lie about my age. This year won't be the last year I'm not ashamed of my age. Instead I will hold my head high and say, "Yup, I'm 30." I vow to end my 20's with a bang, instead of with tears. And I vow that this coming decade will be my best one yet.