Yanno, Miss Priss, it's not you...it's not really personal...if you could look at it this way....from what I've read, it would have been anyone who married your husband...if you had not married him, the lady who did, would be experiencing the very same problems with her...can you think of it that way...would that help some?
Creme my dh says pretty much what you said about Mil would have disliked any woman he married. It's proven over the way she treats/ed my bils wives and gf's and sils fiance. But it's cold comfort to be honest 
It may very well be cold comfort...I've been there and I know your pain...however, if you could change your attitude to believe this and realize, "ok, this is the way she is...it's not me, it's her....and she is the one missing out", perhaps it would be an exercise you could try, everytime it enters your mind.
we can't control other people...but we do have a choice, we can control how "we" think and feel. People used to ask me, when I was having problems with my son and DIL, how I endured it....and I said, I do exerciseds and talk to myself, talking myself out of being a victim, and into the secure person I was...it's not easy...and it takes much effort and perciverance, and it doesn't take the pain away...what it does is, reassured me, that it wasn't me...that I wasn't a bad person, that I was trying...trying so hard to understand her reasons for hating me....and I also realized, that not everyone can like me....and that's ok...I wouldn't allow the bad stuff to creep in, and I kept myself busy, busy, busy....reading, watching movies...getting involved with neighbors, family and friends, and some small travel...what I did was create things for myself to look forward to...and when youstart ignoring the situation...some how, and I don't know how, the other person causing you this grief, realizes she is not getting to you...she is not breaking you down....you are not allowing her to break you down.
I also stopped rewinding....you know, where you take a negative happening, and rewind it to death...trying to come up with answers....sometimes throughout our walk in life, there are just no answers...and people don't do things for one reason but many....so, it was futile for me to rewind. I know the sleepless nights, the feeling in your heart and gut, like someone ripped it out...I know the loss of innocence and spontanious happiness, however, I kept telling myself, there has to be something in this for me to learn. We tend to obsess over these things and it causes us much destruction...don't let it...live and be happy....don't allow this person to bring you down...it's her, not you...and no matter what, fight for who you are, not regret what is...be happy with you, look for the many things you do have which make you happy...and don't wallow in the negative...it's mind over matter and you can do it...you can.
See, these people are miserable...very negative people, and they want everyone else to be to....so, that is why they cause havoc in not only they're lives, but everyone elses, they think and really believe, that, that is life and happiness....
Also, there is something else that may help you understand her....you don't have to love her, or even like her, however, if you can understand why she does the things she does, it may help eliviate some of the pain and self persecution...and no matter how tough we are, to know that our MIL's/DIL's won't accept us, hurts beyond words...
anyway, sometimes, woman, unfortunately, base they're whole purpose in life around they're children....they do everything for them, putting aside they're own lives...which is ok, as long as it's done within reason, however, like everything else...they're are some mothers who base they're entire life, on they're children, and actually depend on them for they're own happiness....and in the process of doing for them, that gives them purpose....when that purpose is taken away....they really get confused...alll of a sudden, they're whole being has been turned upside down and they blame you for it....they can't understand the concept, that what is happening is perfectly normal...and the way of life...and let go, they don't look at this time in they're lives as something wonderful, that now they can do for themselves...they've done for they're kids for so long, that it's been conditioned into them....it's habit, purpose, and they're life...now, take that away and they feel like they are left with nothing...it still doesn't justify they're actions and treatmeant of you....but by understanding that, may lighten your load a bit...I dunno?
What I've written may not be comforting to you...however, it helped me. We cannot base our happiness on other people...we have to find our own and stay there in that comfort zone.