You sound so sad to me OP.
I think that it must be very hard to watch your adult child make the decisions she is making, knowing full well where that will end up.
Some are saying that it sounds like your dd has some form of adhd.
For me though, this screams trauma.
She behaves as though she has no value.
In my experience the people who completely destroy their own public image (by public I mean their outward presentation tot he world) - though lies, unreasonable swearing, dietary choices, aggression with intimates, squandering money, binge drinking, all implies (to me) a background trauma.
We know enough about issues like these now to also know that people do not necessarily deal with, or speak about them.
In your shoes, I would start slowly, but definitely, with boundaries.
Limit the time you spend together, without even saying you are limiting. Meet outside of your home, an hour here, an hour there.
Take the dogs one time out of every three.
If she is badly behaved or nasty an "oh, blast, I forgot X, I have to go." Don't rise to any bait.
Recalibrating a little by being a positive force in life can have enormous impact on a person's self worth; like helping the homeless, doing some reading work with vulnerable kids, reading to lonely elderly in homes or some such.There is so much need out there.
It could even be something positive for you two to do together.
You cannot change her, she has to do that.
But you can help her (and thus yourself) on the qt.
Good luck op. I don't see meanness in your post; I see sorrow.