Mine was the same when I found out he was cheating he said it was my fault cause I was pregnant and not giving him enough attention, then it was my own fault cause if I didn’t break his trust be going through his phone I wouldn’t have known. He turned violent towards the end but I think the fights and keeping me up all night so I couldn’t sleep and I’d just agree with him so I could literally just sleep were worst than the physical side of it. Most of them are so text book thoughOh god the stories I could tell. I've dealt with 2 narcs, my ex and a family member and the gaslighting is unreal.
When we were still together my ex would threaten to split up with me if I went somewhere he didn't like or spoke to his friends without him there because it meant I was sleeping with them. We'd have sex and he'd tell me how he imagined his ex the entire time and how much better she was. He'd completely lose his temper and it would be my fault and if he was gaming and lost that was my fault. It came to a head when I text him about dinner one day and his 'friends' text me from his phone saying he was too busy shagging someone I knew to care if I was making dinner. The fact that same person he was supposedly shagging drove him home didn't really help but somehow I was making it up and jealous. Denied the texts and everything. But pulled up the fact I'd put kisses on a message to a guy I knew a year previous.
I started doubting my own sanity and eventually had a breakdown and had to be sectioned and even then it didn't stop. It's been 7 years since I got out of that relationship but there's still damage there from it.
As for the family member they were exactly the same. I don't speak to any of that side of the family now because they took their side and believed everything even with evidence and messages