A first suggestion, which may help you in the future but not immediately, is not to post your email address on a publicly readable page. If you need to provide it, even a minor modification such as using <at> instead of @ will prevent most spam harvesters from seenig it.
What appears to have happened is that a spammer has sent many emails using your address in the "from:" line. When the email goes to an invalid address, the recipient mail system sends a message to notify the sender that the email couldn't be delivered. In this case, due to the forged address, it thinks you sent the email.
If you are willing to do some extra work, you might consider sending the emails to a site such as knujon.com or spamcop.net where they can use it to identify and stop spammers. Otherwise, I would suggest just waiting for the barrage to run it's course and be thankful that they are going into your spambox, not your inbox.
I have create an Alert about this. Please discuss this there. I have also removed the email and the email addresses to prevent them from spam bots (they crawl the whole internet for email addresses to spam).