I know if you already have been abused, this feels like more. Try not to see it that way. Try to see it as "that's the way she does it", and it has nothing to do with you. It is her doing, so don't take it to heart. As soon as you can place her behavior on her solely it might feel better and you might get immune to the taunting.

When she starts a bad behavior (then I mean something that is mean to others or similar), don't pay attention. If you do, pretend that you don't. If she has not learned how to get positive attention, she rather gets the negative then none. I know how cliche it sounds! But I think it might be true. That doesn't mean those people should go through life without attention, but like with a troubled dog, you reinforce the good.

She might feel bad about herself. Easy to try to make others feel bad, hard to make oneself feel better (My friend does this!). I try to just tell her she is fine when rarely it bubbles up she dislikes things about herself. I hope that will some day deal with the hostility she has towards others, even if in this case she mostly does it behind their backs.

Nothing my friend does (she never had ODD as a child but she has some traits) is her own fault. It is bad luck or someone else did it. I think here she actually have to think it is because it would kill her to admit she is lousy at some stuff, ruining and misplacing things. She doesn't see cause and effect. I do try to say something positive when she actually manages something, in a way that doesn't sound like if she is a child, but between peers. So she feels she has some control.

I try as much as possible sort of just try to hint to her that we're all the same and she is not less than anyone. The things she is really good at I take my time with.

She is also very impulsive and can get angry fast. In her case, not eating right really makes it worse! She could take your head off just because she is hungry.

So in her case I think there is a mix of actually have some deficiencies that she doesn't know how to handle, and things she has picked up because of other people's negativity towards her or ignoring her.

I think you maybe have to walk the fine line here not even just because she is an adult but because she probably always needed independence and control, to make the positive attention not sound like you are talking down at her, but also offer it readily.

I don't know how to put someone back in control of themselves. In my friend's case I think she will always be a victim to her scattered thinking. But the more someone can see they CAN handle things, the better they feel about themselves. Don't pick on accidents and accidental failure. Or on bad emotion that is not directed at anyone. And people, like dogs, even healthy people, respond to positive enforcement.

I know this can be hard to do towards a negative person, heck I know it so well.... but after you start it won't be as bad.

When my friend panics over small things, I shrug it off (even at times I myself might feel affected), and I say "nobody died" or "at least it didn't kill anyone". Just as a statement or with some honest humor.

She will hurt your feelings and for now maybe don't even expect or ask for an apology. Try to ignore all hurtful things as it is just a way of sucking you into arguments that lead to nothing, because at least if you argue, you interact. She might not even know how to interact on a neutral basis.

I might be totally off and in that case I apologize. I just take what I learned from my friend.