I would definitely try moving this baby down to a smaller tub. 70 gallons is a lot of space and doesn't offer nearly as much security as this baby may think it needs. Even with a multitude of hides, it may not be getting the right feel for comfort. We always think more space is great when really, she may just need a little cramped 6qt or 12 qt tub for a few weeks.
Honestly, this may be why she was giving you so much trouble feeding as well if that was her first setup.
Set her up in a little tub. Make sure the temps are good. The frosted look of the sides is usually enough to settle them down some, but you may still need to offer a little hide box or can tape some dark paper to the outside.
Give her some time to settle in. No handling at all. And then try with short little sessions after she's gotten 2 good meals in.
Baby steps from the beginning and hopefully she'll turn around for you. This is what helped for my feisty defensive babies