Mil won't come to Christmas

I was asked by my husband's family to host Christmas months ago. I agreed. I've spoken to the whole family had multiple conversations with my MIL letting her know we can accommodate them any time they prefer we could pick them up and take them home or they could stay the night. In a family group chat I forgot to include my MIL. Not a huge deal I caught the error and sent her an apology.

She never responded to my sincere apology and called my husband to tell them they were not coming to Christmas. They are staying home.

My husband is perplexed and angry and told me I need to fix this as it's probably his father's last Christmas he's 84 and has dementia. I've had so many conversations with my MIL prior and had told her all the details just not in a group chat a couple days prior.

I've been beside myself with grief that they won't come for the rest of the family's sake. My Mil hates me and claims to be a Christian woman but doesn't forgive or apologize. She tries to control every situation. Has gone so far as to put her hands on me at one point over the years. My husband is a mamas boy and I never make him choose sides.

Well this Christmas everyone got involved now because it's ridiculous she won't come and I tried to fix the issue weeks before Christmas. My brother in law called her and old bitch. I've asked other families to host and no one will for the principal of point that she doesn't get to treat me like crap.

My own husband hasn't said anything to her though. I'm worried he will hold me accountable for the ruined Christmas and the relationship with his mom. After over 12 years I'm terrified this will be the end of our marriage. I'm worried his whole family took my side and he feels the need to defend his mother even more.

I'm honestly a good daughter in law she has absolutely no idea what a bad one is. I just know this family dynamic is so stressful for me makes me literally sick with fear.