Gah! Writing gods, why do you hate me so?

I've been working on my writing for about a half an hour now so far this morning, and it's like this:

1. I write a little bit
2. It sucks and I delete most of it
3. I sit there and spin my wheels in place
4. Go back to 1. Wash, rinse, repeat.

I can't seem to write a paragraph without deleting half of it! I've written probably about 500 words so far today and I only have 240 to show for it. And even those 240 words are blah. Just blah. :(