changedname,
re your comment:-
"It feels like a lot to throw away a relationship with good points as well as bad without seeing if things can be better"
And that is the sunken costs fallacy right there!. Do not fall into that trap. The sunken costs fallacy basically causes people to make poor relationship decision. If you do go back your children as well as you will suffer yet again. You have a choice re this person, they do not.
The idea of sunk cost states that an investment of money, time or energy must not necessarily influence your continued investment of money, time or energy. The past investment is “sunk” into the endeavour and cannot be recouped. It is gone. Ongoing investment will not resuscitate what is gone when the investment/relationship is a bad one.
People get bogged down by focusing on their sunk costs. You certainly are now being bogged down.
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. 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.
Do enrol on Womens Aid Freedom Programme, this will help you as well.
Abusive people are not nasty all the time and I am certain he was charm personified to those in the outside world. However, the nice/nasty cycle is a continuous one. Those "good times" if they really were so likely became fewer and further between as he ramped up the power and control against you. Also its not just you who was and still is affected by his control.