Kids and Finances mostly....
Kids - This is the real tough one. Do I do more harm than good by being there? I'm resentful towards my wife all the time, I go out twice a week to the pub to drown my sorrows, I have a tendency to have a short fuse at them when they're just being kids because of my resentment towards my wife. I lash out because of the constant BS she covers our life in. However, if I was to leave I'd be 60 miles away, would see them one day a week max, then would her issues be targeted to them rather than me?
Finances - Everyone would be worse off. No holidays for the kids, not as nice clothes, toys, day trips etc.
I know if I were to leave the house I pay solely towards would no longer be anything to do with me and become hers, half my pension would no longer be mine, I'd be paying £900 a month in child maintenance and probably an amount for spousal maintenance. I'd have a more expensive commute, a longer commute and have to pay for weekly car parking. I'd be left with approx 5-10% of my monthly take home wage.
I have no justification to stay in terms of feelings for my wife, our families outside of the children, we have no shared friends, or interests. My mental health would probably be massively improved in terms of treatment but destroyed with the stress of kids upbringing and financial shackles.
All in all I just see life as an existence now but will honour my responsibilities to the kids.