You have done all you can, and have been a great daughter in bloody awful circumstances. You truly could NOT have done more. Believe it.
This is a valuable statement Good, but I'll bet that you can't bring yourself to think it's true. If your M clearly still isn't happy, that must surely mean that you weren't good enough. I think we can all tell you with some confidence that you could push yourself to absolute breaking point and be hospitalised as a result of trying to meet her needs and it STILL wouldn't be enough. It never ever will be.
Therefore, you should prioritise your own needs. She sure as hell won't.
I agree that you sound a little disappointed, which is totally understandable. Try and use that disappointment to reset your expectations a bit, so you're not as disappointed if when she acts like this again.
Oh and YY to this: By the way is she likely to come over to your place? Don't want her thinking you are escaping DH's clutches or acting like a homing pigeon in visiting the old place.