I have been married for 20 years, and my MIL was the exact same way - she had nothing nice to say to me or about me, ever. She did not get along with my FIL, and since he actually really liked me, she did not. I almost divorced my DH because it hurt me so bad that he didn't seem to care enough about our marriage to defend me when his mom was being awful.
Really, for me, that was the crux of it, the fact that my husband did no defend me, because he didn't think it would change anything, and he would rather have me upset and hurt than to stand up to his mom. She treated him like the sun rose and set upon him, he was so wonderful, but even our children were treated poorly by her, because hey, they came from me! He didn't stand up to her, even when she was mean to our children. It just wasn't worth it to him. This made me feel like me and our children were just not worth it to him, either.
Eventually, I just didn't go to see her anymore, and did not let our children go to see her, either. It still hurts me that my DH did not stand up to her, but after 20 years of marriage, I suppose his other redeeming qualities have helped me push down that hurt and not constantly beg him to tell his mom to stop being mean to me and our children.
One and a half years ago, my MIL had a couple of strokes that she did recover from. Now, she is incredibly nice to me and our children! It is as if all the words and actions of the previous 18 years never happened. I don't mind answering the phone now if she happens to call, and the kicker, she has set up savings accounts for our children this past year and also paid some of eldest DD's college tuition! Sure, she did this for all the other grandchildren since the day they were born, but I am thrilled she is acknowledging my children now, when she never did before. I would have been happy even if she had just started being nice to them, but she has gone beyond that, and I am still amazed at the change.
I suppose what I am trying to say is, things can change. They may not, but you just never know. You may feel like your husband isn't holding your worth above his mother's, but if he has other qualities that are still there from when you married him, focus on those redeeming qualities. Yes, you are hurt, it is so painful to feel that your spouse is not protecting you from the hurt his family is causing. Try to remove yourself from his family, and see if that can help you clear the cloud of disappointment you have in your husband right now, and perhaps then you will be able to focus on whatever positives are in your marriage. Sadly, accepting that he will not change is going to be incredibly hard, and very hurtful and disappointing, but if your marriage is strong otherwise, you will be able to put this aside.
And as I always told myself (after I entertained the thought of divorcing my DH because he didn't stand up for me), leaving DH would be the one thing that would make the MIL happy, so there was no way I would give her that satisfaction!