Oh I'm sorry @Faith-and-Hope that your Mum has died, I hope that she didn't suffer. Its the longest relationship we all have, that's where we all started.
If there's less aggression, anger and violence, it would be easier to hide his mental illness, and if he was away a lot travelling he would of had other outlets.
Personality is a fascinating thing, to turn on your own birth family without any major reason to, is indicative that more has been happening mental health wise than anyone could see. Most Aussies in the community have never even heard of personality disorders being a legit MI, let alone NPD. People don't take it seriously, and I think that Psychiatrists are more likely to diagnose BPD, even if they are seeing more NPD because this can encourage the patient to try DBT and other therapies.
I really hope that you get a resolution this year. We got no resolution, our aunt packed up, sold her house, left Sydney and never repaid moneies owing, ignored lawyers, ignored the ATO, there was no inheritance for us, or I think of it more like some compensation......whatever happens you will get through, and adjust to life how it is; you haven't been given a choice. I am so relieved you don't have to grow old with him and be his servant. You're free to enjoy the cubs, grandbabies and furry friends - Corny