I think LeeD offered a great post...I'm not truly sure what else I could add onto it. Offering advice to marriages is not my strong suit...there are so many factors, so few of which I have ever had to deal with, that it is hard for me to put myself into the appropriate perspective to offer much advice.

I am sorry I cannot be of more help to you.
I would only tell you, though, that at the end of the day, you must do what is best for you and your children. I understand so well how hard it can be to leave a toxic relationship. Though I would be severely minimizing your situation to compare it to my former one (thus I'm not, only offering my experience), I willed myself through my relationship with my ex out of sheer hesitation to leave. I could not convince myself, though I knew it was for the best, that it was what I should do. I relate that to you to tell you that you are certainly not alone in that regard.
I wish I could offer you more concrete advice. I am sorry I cannot.

As I said, ultimately, you must do what is best for you and your children. Please know I am praying for you, and that I hope things work out. If I can do anything for you or if you ever need someone to talk to, please consider my PM box open at any time.
Hugs, and all my best,
Harley