Dang, I felt that I shouldn’t have followed that guys tutorial on YouTube. And no, I never attempted to change the region, the errors just randomly started happeningYou should never follow Youtube guides as they tend to be outdated or incomplete. Like I said, if you didn't follow http://3ds.guide when you hacked your 3DS, then it may be difficult to help you. It's too late now to go back and try to do it again.
Unfortunately none of those are typical errors and it is hard to say what the problem might be if your SD card has passed testing. You didn't try to do a region change, did you?