Hey, hun, I am so sorry to hear that it got worse, but should know that you are not a disappointment. Don't ever allow someone else to make you believe you are. Your mom is definitely so mad at him because she sees the fault in him and not you, you tried so hard to talk, compromise, find solutions and you are still trying to find the fault in yourself - you are so so compassionate.
This is not your fault. And it's okay to feel empty and it's absolutely ok that you maybe don't know how to feel about all of this. The man you thought you would spend your life with turned out to be someone very different from who you believed him to be, that's incredibly hard. Take your time to figure everything out. Take time with your mom, the dogs and maybe talk to some friends, even if it's hard, but don't worry about us, we will be here, the entire time, patiently waiting and rooting for you! Like the comments before me already beautifully pointed out, we are here for you and we hope that you will do, what is best for you. If it is already such a relief to not having to face your mother-in-law then something is definitely wrong and you shouldn't be forced to deal with that forever.
Ultimately a marriage is between two partners who need to compromise and if it doesn't work out for whatever reason, that is also between those two people. Everyone that cares about you and your well-being and understands your struggle would never even think to consider you a disappointment. You are just protecting yourself and that's so so important!
However, I do have to say, if you find a way to compromise, a way to reconcile this whole mess after all, we'll be behind you as well, of course. But in that case, make sure you can trust your husband and trust in your communication. We just want you to be happy, remember that <3
xoxo Sazura