Yes... don't panic.
You should buy a cheap little USB Adapter for your SD Card, so you can download the ROM again and put it directly on your SD card... if possible do this at the library or someplace with a PC.
Then with your device totally powered off and the sd card with your newly downloaded ROM in your device... hold down the Volume Down button, then press and hold the Power button, hold both down for about 5-10 seconds... your device will boot up in hBoot mode, a white screen with writing on... this is where you normally boot up to load a new Radio... select Recovery... wipe data, wipe cache, and wipe dalvik cache, then install your new ROM.
If you don't know how to do this in Recovery, then you can also see instructions in the link in my signature below on the "[Tbolt] How to for ROMs" link, which goes the sticky thread at the top of this forum.