From what I remember back then on old posts from people who knew her and associated with her (long deleted now) a mixture of her and Cory splitting up, along with some family stuff, the time she got caught "stealing" (walking out with a pair of sunglasses) and getting a fine from that, and her already having psychological problems she had a bit of a mental break down. I think originally she tried to say her channel was hacked and that's why all the video's were deleted but she later admitted to wanting to get rid of them all.