Re your earlier comment
"I think if it wasn’t for the kids and being together so long I’d have left"
It is for these children that you should leave your, and in turn their, abuser. Sound travels and it is highly likely they have heard far more than you realise here. They certainly pick up on all the vibes, both spoken and unspoken, between you both.
Stop doing your bit also to teach them such damaging lessons on relationships by at all staying with him. Staying for the kids never works out and is a particularly stupid idea in your circumstances. Do you really want them to grow up thinking, yes this is how men do treat women because mum showed us this was acceptable to her too?.
Being with him also because you've now for x number of years is still no reason to stay with him and is an example of the sunken costs fallacy prevalent in relationships. A bad investment here is not going to sudden come good and people get bogged down in their sunk costs.
There are two ways to understand this process, both involving avoidance. One is an avoidance of disappointment or loss when something doesn’t work out. When a relationship doesn’t succeed, especially after a long period, especially after many shared experiences and especially after developing a hope that the relationship would be a good one, it is a loss. It is a loss of what might have been and an acknowledgement that a part of one’s life has been devoted to this endeavour.
Another angle to evaluate is that focus on “sunk cost” creates a distraction from one’s inner truth. The sentence often goes like, “I’ve already invested to much, so I can’t notice my thoughts and feelings that are telling me to end or change this relationship.”
This is a type of insidious defense against noticing yourself and this is what you are doing to yourself now. You enter into a neglectful relationship with yourself which divorces you from your inner thoughts and the quiet feelings that might guide you in your life. In other words, thinking about what already has been may prevent you from deciding what you want your life to be.