Stuck in boot loop - how to clear cache?

Ok... so I'm stuck and I've been googling and playing with this thing for about 4 hours now.. I'm stuck.
Basically I got S-OFF, installed the stable cyanogen release and got it up and running. I was having a few issues and just decided to go back to my stock installation. I downloaded the RUU package and flashed the ROM onto my phone. Rebooted, the white HTC screen comes up, and reboots, and reboots and ... well just keeps going. I can get into the HBOOT (volume down + power) and I can see the menu, but if I select RECOVERY or FACTORY RESET the phone just goes back into the reboot loop. I need to get into the menu where I can clear the cache, but I can't get there. Is there a way to flash it or flash the cwm recovery (partition?) without using my pc? I can remove the sd card and put files on it... I was able to re-flash my stock ROM hoping it would help, but it doesn't change the bootloader. I can't connect via USB to the phone... otherwise I think this would be a simple procedure. Maybe it is, I'm just missing something.. I've been at it too long.
If anyone could help... please let me know if I'm not giving enough information, or set me on the right path. Thanks!

-Revolutionary-
VIVO PVT SHIP S-OFF RL
HBOOT-6.13.1002
RADIO-3805.06.03.16_M
eMMC-boot
Apr 1 2011, 18:34:39

if its going to CWM recovery mod...then open recovery...try wipe data+cache and dalcik..
then format system ( in mounts)
then flash stock back...it will work

Those options didn't work... just rebooted the phone and started boot loop over again.
I let a friend play with it and he got it working... he was able to connect to it over usb, unlike me. Perhaps my drivers were corrupted on my pc. Either way, it's fixed now.