If you can't get the stock ROM to flash again, you could try the SJHill 3.0 ROM on SlateDroid. It takes an SD card & 10 minutes to get installed & made this cheap, little tablet a usable device for me. Sped it up & got rid of the bloatware. If you didn't like the ROM, you could attempt to flash back to stock after putting it on, which should go more smoothly.
"Have you tried turning it off & on again?"