Unfortunately, there is no way to cause your mother to change her behavior. And when attempts to resolve through discussion "go up in flames" then that is a sign you need outside help, as in family therapy. I realize it is unlikely your mother will agree to that suggestion, which also is unfortunate because without intervention, the encounters between the two of you will continue to be abrasive.
One thing you MUST do is block your mother's accusations from getting in to you. Your assessment that no matter what you do, it will never be enough, is quite likely an accurate one. So, your mother's opinion needs to remain just that, an opinion, not an accurate reflection on you. One technique that I've used with negative abusive people is to mentally construct a thick, impenetrable transparent "wall" between us, and when their abusive, hostile, and negative remarks come flying out their mouth, that energy projects forward, hits the wall, slithers down and pools around their own feet, so they end up standing in their own $#!+. When you know you have done your best, and when you know that your parents are not going to change, and when you know that your attempts at change haven't worked, then your objective needs to be keeping their stuff out of you. If you want, you can list the things you recently have done when she goes off on you, so that others will hear something of the other side of the story. But even that may only further irritate her, so you have to decide how much you want to espouse truth and how much you want to keep peace.
Remember this principle: Whatever other people say or do is always about THEM, never about you.
Example: I answer your question on Yahoo Answers because I have a need to be helpful and value the needs of others as much as I value fulfillment of my own needs for me. Your dilemma merely offers me a way to fulfill those needs. My own perception is that there is a lot of distress in this world, and whatever can be done to help alleviate that distress is a worthy use of my time. Promoting peacefulness is a value that I hold.
If your mother has a need to lay blame and spew negativity toward you or anyone else, it is because she is relieving herself of the negativity which festers inside her. It is kind of like when a pimple or boil
breaks open and gets pus all over everything near it. Her spewing is about her, not you.