I've only read your posts op so sorry if you've mentioned this.
Is your current house which you live in paid up or do you have a mortgage on it? You say the house is in his name alone.
Something doesn't sit right with all this, if you move and take on this mortgage will he have the main home and what are the payments on that. You really need to see a solicitor before you go ahead with moving out.
You need divorce, with a SHL.
You clearly have seen the light but may I suggest you are only now beggining not to trust him, there is still so much to distrust about this man.
He sounds very manipulative, it's almost as if he is allowing you to see his vile behaviour, he wants you to react, there is a reason behind this change.
Men like this leave nothing to chance, did he leave that email for you to see, has he set up this mortgage for another reason, has he told you about this key episode for another reason, such as telling others you have denied him a key, could he be discarding you and making you think you are the one engineering the end.
My spidy senses are up, and you have been controlled and moulded over the years to believe him, why would the ending be any different.
Cover yourself as much as possible, seek financial help, change passwords and make sure he doesn't have access to your phone or laptop through spyware.
Read up on narcissism, the best reading I found was HG Tudor, Knowing the narcissist.