What Mink said.
DA, particularly EA, although there is rarely DV without EA, changes the way you think, the way you perceive things.
It obliterates your sense of self, your confidence and your perception of what is normal. You know what is going on is wrong, but until you are out and recovering you cannot quite grasp just how wrong it is. On top of all of that you are constantly mentally exhausted from it.
It's very easy from the outside to look in and say what needs to be done, but when you are going through it, it can feel impossible.
On top of all that you have the abuser throwing you just enough niceness to have you question yourself constantly.
The only person responsible for what OP's children are seeing is the abuser.
OP, I agree you cannot just pack up and leave, but don't plan for too long.
I would go and talk to CAB and ask them what, if any, support would be available to you. You don't have to act on it straight away, but it is a start. Take things one step at a time, rather than looking at the whole process of ending the relationship if that makes things easier for you. The first step being CAB.
It is easier living without a man like this in your life. I know you think you know that, but I'm sure if you are honest, fear is part or even most of what is holding you back, as opposed to needing to plan and that's okay, that's normal, but don't let that fear paralyse you. Start your plan on monday, one step at a time.
A lot of posters on MN would do well to remember OP is already being told it is her fault at home, hearing it on MN will not help give her the strength and confidence to see her plan through. This man has had 14 years to convince her that she is not good enough. That's a lot of damage, it cannot be undone because a stranger on MN said LTB.