Managing divorced parents at the wedding

[Florence87]

My parents divorced quite recently, just few years ago after being rather unhappily married for 26 years. My mom caught him cheating. I got engaged a few months ago and a month later with little notice my father married the woman who he was with when my mom caught him. I live in a different country so only met her and her family a few times, they were very nice to me, my father is very happy. I am polite / neutral with her. On the contrary my mom is not doing great at all, she is still in a complete breakdown and a month after engagement she made a scene that she does not want my father at my wedding and hang up on me. When she found out i speak to his new partner she refused to talk to me ever again. It’s been a couple of month now, i tried to reach out but she blocked me. My mom is not really a very reasonable type, i try to take care of her and cheer her up but I cant just sit and talk to her peacefully, it is always a drama when it comes to my father. My grandparents are on her side. I mentioned to my father that i will not be inviting his wife as i don’t feel comfortable making the whole situation much worse and also because i really dont know her well to which he said that he may not be coming then.

What do I do about it? It looks like it maybe the case that neither of my parents will come or if my father comes with his wife i may never be able to fix the relationship with my mother....