This! DH and I have long experience of this. 6 years now.
It’s not his personality that has changed, it’s the fact that his brain is damaged and of course this will impact on his behaviour.
He says that he sees his outburst as normal behaviour. He doesn’t have dementia, he is a sweet, loving man, but he has had a life changing episode.
We are now going through melt downs and anxiety. I am giving Blessed CBD patches a go, I don’t know if they work but they are not going to hurt him.
It’s hard! We do continue to communicate and I do tell him how I feel, which he acknowledges and he apologises.
Reaching out to MN is a good step, you are not alone. You do have to look after yourself. And encourage him to keep active, if possible and
try to hold onto any amount of aware of his actions he may have. Because total lack of awareness and constant blowing up at you is not sustainable.
Is he depressed. We had a look at that with the GP, DH decided not to go with anti depressants.
Oh, and this is quite important, he was diagnosed with emotional lability. Look it up!