It's very common to feel embarrassed and ashamed, it's perfectly natural. Try not to think about the footage, there's nothing you can do about it.
He didn't change OP, I'm telling you that he was always abusive and the abuse escalated. And no, it has absolutely nothing to do with anything you did or didn't do. Many survivors bend over backwards trying to become the best possible version of themselves to stop the abuse but the goalposts always move.
Abusers don't like women and see them as enemy combatants. A relationship is about power and control and having the upper hand. Your relationship always had a power differential because he was your carer and you were dependent on him.
Abusers are very good at masking which is why friends and family think he's the bees knees. However, I 100% guarantee that this didn't come out of nowhere.
Loneliness is literally a killer. Too many women stay in bad relationships because they're frightened of being alone and it's been shown to shorten lives.
My advice is to keep busy and not toss and turn. Watch a comforting box set, join a hobby forum and chat, phone a helpline like the Samaritans, teach yourself knitting, practice yoga, journal, make plans. You're going to be ok💐