Stormwhale.
A man who's having a massive personality change due to neurological things does NOT
Tell his partner she is over reacting. Does not regularly make her feel guilty. If you look up thread she says 'I don't want to say anything because he'll make me feel guilty'
These are the insidious emotionally abusive behaviours that can go on and on for years and years before an actual event that it overt abuse happens.
It's about power and dominance. Abusive men may not be physically or overtly abusive for years, or ever. Changes in circumstances can trigger new abusive behaviours.
I think if OP looked at some of the literature on abusive relationships, I'm sorry to say, that she would recognise many tactics.
It's common for women in these situations to only see the good time. This is called the 'cycle of abuse'
I will hold my hands up if I'm wrong.
I was with my DH for 10 years and it took only a few overt incidents (though in hindsight there had been lots more which is brushed off, excused or whatever) to get out and much longer to realise I'd been abused for years.
Ive done courses and training and read and now do activism and campaigning. I speak with lots of women. This behaviour, as someone else said, is textbook.
If I'm wrong I'll happily eat my words.
Sorry OP. I know how hard it is to read this stuff. You are not alone and you will be amazed what you can do and achieve without him. Huge hug