I do something wrong. It's my fault.
She do something wrong. Somehow magically it's my fault again.
Most Helpful Girl
Most Helpful Guy
The theoretically simple answer is to break up and move on.
If you need to, I'd suggest doing that.
However, I think you'll find that most women behave as you describe. The way to handle it is to hold your ground. Basically, the simplest advice I can give you on dealing with most women (not all) is to treat them like small children. You would not come and ask me how to deal with a five year old who blamed you for everything. You'd see it as obvious that the five year old is simply acting on emotion, and that you're the grown up. When you do something wrong, you'd apologize genuinely, and mean it. And when they do something wrong, you'd hold them accountable, and be willing to move on and forgive them, but not remotely consider them blaming you. You'd hold your ground and if they threw a tantrum, you'd view it as a tantrum, and either say so, or make your point then leave them alone till they calm down and apologize.
Your mistake is treating people as adults who behave as children.
I imagine some women reading this will be angry. So let me say this: I don't date men, perhaps many or even most men behave like this as well, I don't know. So perhaps what i'm providing is good advice for dealing with people in general, most of whom are far less grown up then they appear to be.
If you can't do this, break up and find one of the rare people who self regulates on their own.1