User, I think you have let your dd con you into believing this is about her way of delivery. It isn't. It's just a tree she has chosen to hang her general unhappiness on, and she perseveres (rather unusually) into doing this in adulthood because it works: it makes you unhappy.
a) the teen years
Let's face it: most teens feel scared and unhappy at some time. They look around for somebody to blame, they see their parents, and they try to think of something hurtful to say to them. My teen blames me for being "too posh". Other teens blame their parents for being too poor, or too strict, or too unkind, or too old, or too young. The proper response (unless you feel they have a genuine grudge about something you could or should change) is to tell them that you are ready to sympathise about their troubles but that you really won't listen to this silly complaint. End of story. Teenagers need to feel that their parents are a rock which they can lean on.
b) adult age
This is trickier, but a modified approach might work here too. Tell her calmly that you love her and are always ready to help her or listen to her, but that as for her delivery the best decision was made at the time and you really aren't prepared to discuss that any further. The calmer and more brisk you can seem, the better.
What is clearly happening is that she feels very uncomfortable about the choices she has made in life, she may have felt judged by you for those choices (how tactful were you when trying to get her away from her unsuitable relationship?) and now she desperately wants to persuade herself that the wrong choices were made by somebody else, not by her.
When you talk about your helplessness, you mention your inability to shout and swear as if that would have been the way to make an impression on an angry teen. But it isn't, you know, it really isn't. Doesn't work with adult children either. What can work, if anything works, is a cheerful kindly attitude (faked if necessary) - because that gives power in a way that ranting doesn't.
You are probably right in that there is something wrong with her. But if you model helplessness in the face of her onslaughts, she will know that you cannot help her.