Merlot
This does sound like a difficult situation. It appears to me that you and your wife have reached the stage where you are in opposing corners with neither of you prepared to compromise. This is very destructive for everyone, especially the children.
Is it possible for you to find a way to spend time together away from the situation and really talk about what you want? Try having a talking stick and taking turns - or maybe an egg timer? And set some ground rules ... this is not about blame or being "in the right" but about a sensible way forward which may or may not include separation and divorce. It is perfectly possible for you to go to a relationship counsellor on your own. You do need to do something to defuse the anger you are feeling - and so does she. You cannot do it for her, but you can do it for yourself.
I think this is what you need to do first and foremost. Look at your life, look at what you would like to change. See if there is a way to become the husband and Dad you want to be. This may mean you move to Devon now - not at some indeterminate point in the future - and learn to be happy with a lot less cash but perhaps with much more time for each other and the children? This is a much easier path than divorce. Single parenthood is no picnic.
If divorce is inevitable, there are many ways the assets may be divided. Look at section 25 of the 1973 Matrimonial Causes Act for some guidance. 50:50 is the start point but often not the final outcome.
As there is inheritance cash tied up in the property, this may make a Mesher Order a more attractive proposition ... This would mean you get a share of the property on sale - but it is not sold until say the youngest is 18. It can also apply to any new property that may be purchased.
A
pension share is also a possibility. You need to get a
CETV - cash equivalent transfer value - for the pension.
Some SM on top of CM may be in order but it is possible for this to be time limited - say to allow for the mortgage payments until the property is eventually sold? Remember she would get tax credits as a single parent which will boost her income significantly if she works part time.
But all this is jumping the gun. What you need to do is have a proper talk with your wife (*not a talking to) respect her views and see if you can work together for the good of the children. They are the most important people in all this.
Hadenoughnow