Issues with Galaxy Tab 3 Lite - update keeps restarting

I just got a notice on my Galaxy Tab 3 that there was an update available. Of course, I end up pushing the update button and waiting for the update to finish.

Instead, the update restarts each time it reaches 25%. There's a brief flash of the green android with a red exclamation mark over it, the GT3 logo appears briefly, and then it starts all over again from 1%.

I've tried everything to fix it, including resetting the entire device. It just won't turn off properly - the "volume button, power button and home button" trick reboots the tablet, but it goes RIGHT BACK to the update screen instead of letting me access the main menu. I'm thinking it might have something to do with space issues? I would love to delete the extra data from this thing, but it won't let me due to that stupid update screen that just won't go away.

I have no idea what to do anymore. I should probably just throw this tablet into a wall... it's so unwieldy and difficult to use it might just as well be broken.