Did I just brick my HTC One X
Don't panic. Try this:

On your computer, browse your ROM .zip file, there should be a file named boot.img at top level. Extract it somewhere on your computer.

Plug your phone into your computer via USB cable.

Boot your phone into bootloader mode. (Power + Volume Down button for 5 seconds.) At bootloader screen your phone should say FASTBOOT USB.

Assuming you know where your fastboot.exe is on your computer, issue this command in cmd:
path/to/your/fastboot.exe flash boot path/to/your/boot.img

After that restart your phone and see if it can boot into your ROM:
fastboot reboot