If I understand you correctly, you're probably boot looping over and over, right? This happened to me a few weeks ago, I accidentally did a FULL wipe, then I had no OS and nothing I could flash (I was in a car). When I turned the phone on after that, it would just boot to a white screen and start over. To shut down your phone, try holding Power + vol-down until you can get to the boot screen, then power down.
To fix it, you'll have to put a ROM on your phone. From that boot screen, go to recovery (clockworkmod, in your case). With your phone connected to your computer, use adb to put a rom on your SD card, then on your phone just flash the ROM like normal. that should get you up and running.