The way I see it, my two best courses of action would either be to try and return to a stock ROM so that I can send the device in under warranty or to continue to try to fix it myself, which has been less than successful so far. Every process I have found online to return to stock seems to end in fastboot oem lock, which won't do anything for me as my phone doesn't show up in fastboot devices, file explorer, or seem to be recognized by my computer in either Ubuntu or Win 7. I've tried connecting on my friends' computers with the same results. I've also tried using another USB cable. No dice.
Sorry if I missed something obvious before posting. I tried to do a lot of research online and have reached the end of what I know what to do. Any suggestions?