OP,
Your situation is so similar to mine. For various reasons, I hung on far too long (although, tbf, ExH was also good at manipulation situations so it was almost impossible for me to leave - including financial abuse)
I opted for splitting, and it took me nearly 2 years to get him out of the house. He wouldn’t leave, as he ‘believed’ it to be in the children’s best interests to not have a split family!
Anyway, long story short, he finally went at the beginning of the year, and honestly, it’s never been better. Aside from the fact that I know the dc are stressed when visiting him. That is really hard to accept, but ultimately, I figured that 11/12 days of peace, calm and stability, and 2/3 days of more chaotic, stress filled time each fortnight was better than the utterly awful example of family life they were getting when we were together.
Eldest 2 dc (young to mid teens) pick and choose when they want to see him. Middle dc in particular struggles with spending expended time with him, and mostly,doesn’t want to stay overnight. Youngest is currently too young to choose, but even they have started to chat openly about aspects of life there they don’t like.
All I can do is support them through this.
From my perspective, I would say onwards and upwards.