Questioning my sanity

Seeking help, because I'm questioning my sanity and reality. Non-adhd spouse. Very soon to be ex-spouse. After 3 years, last month I put a firm boundary in place and have stayed true to it this time. After years of being yelled at, sworn at, public scenes, this has come to an end for me. 

My spouse has taken this news from one extreme to the other. From literally rolling around on the floor sobbing (zero coping mechanisms) to sarcasm and continued criticism. 

The last few days he has been aggressive, sarcastic, calling me a gaslighter, a manipulator, and telling me that I am being toxic and taking his words and using them against him. I have tried to stay calm, compassionate, and kind. I have stated that the boundary is for my health and sanity. That I care about him and love him and am not asking him to change. I have apologized for ways that I hurt him over the years and taken ownership of my failings and difficulties. But I am in a non-stop barrage. I had to tell him to leave (he is not staying with me but has access for a few more days) several times because he was speaking critically and I wasn't going to engage. Another sarcastic text yesterday. And then calls today and is dismayed and confrontational when I am not warm and pleasant. That was followed by a text that I was manipulating him with toxic behavior. 

In all of that, my question: Is this type of behavior what anyone else is experiencing?? It feels like madness. He makes a choice and if I don't respond how he envisioned or hoped, the entire narrative is shifted. I am struggling not to lose sight of myself and reality. Seriously, I'm losing perspective. Does this happen to anyone else?