MIL situation

My husband and I separated in november due to my mental health, and his mother, I found out hates me. She has posted numerous times about me on facebook. Well today, her and my husband got into a fight about me. And I got these messages. He has already told me what he did when we were separated, but he promises me he never did this. I have had enough with his mother so I blocked her. Should I have blocked her or should I still try to make a relationship with her. I dont want his family torn apart, but I dont want the one I'm creating to be torn apart.