Ah well, a view from the other side here as well!
Have no doubt in my mind, he is playing you both
My XH told his OW, we were as good as seperated, seperate bedrooms, no sex, planning to divorce, funny enough that was all news to me Yes we were having problems, but had never discussed seperating or divorce!
When I found out about the OW, I went completely batty, and I am a fairly reasonable rational well educated person Yes I did some things I am ashamed off and some of those were fairly nasty texts to her, but what he was doing and saying pushed me to the very brink, and he very much made it all her fault!
It took me a long time to figure it all out and get rid of him
Have no doubt OP, in her mind you ARE the OW, and enirely to blame for her marriage breakup, have no doubt he is cultivating that! She is angry, hurt, distressed and hitting out at the one person it is "ok to blame" ...you!!
The harassment and threats are of course unacceptable, but IMO understandable!
As to the divorce, well my XH has fought me at every turn, been a complete arse and my absolute took almost exactly a year to come through!! No bloody way, if he wants to be divorced and move out should it take 18 months, and no way does he still NEED to live there!!
If this is in fact the kind of man you want to live with and be with, the best of luck to you, I suspect you will need it!