Why is it so hard to blog?

Why is it so hard to post my first blog? I've had this site set up for months now. Spent ages messing about with style and colour and format and images. But, and this a crucial but, no content. No words. As a writer, this is a serious crime.
 So why no words? Do I feel under pressure to make it snappy and interesting because I've got my MA in Creative Writing now? Is it just because I'm quite a private person and putting myself out there freaks me out a little bit? Or is it just because I'm lazy?
Why have I decided to blog? These are the reasons I can think of off the top of my head.

• Now that I've finished my MA, I'm trying to become noticed as a writer. And I keep reading that a writer should have an online presence.
• Writing is a muscle and needs to be exercised, this is like going to the gym in writing terms.
• Since I hit my thirties, I've become a lot more ranty about issues. This is a good way for me to vent my feelings and save my boyfriend's ears.
• I used to keep a diary, and I miss the stream of consciousness that springs from just writing about your day and what's been happening in your life.

So here goes nothing, my first post.