Hey Geordie2,
Welcome to Wikivorce. You are deffo not the first (neither was I!), and I am certain you won't be the last to face this life-changing situation.
My wife decided for 'us' a year last January. No discussion, no input, just 'it's over'.
An oft used phrase used here is 'it takes two to tango, but when one leaves the dance floor, what then?'
You will find a lot of people in similar and sadly sometimes much worse circumstances than yourself here. There is no magic wand. The pain is scorchingly real, and the aftermath messy. But it is not the end. It will and does get better. We come out of this process as different people.
You might find it helpful to read the Wikivorce Step by Step guide to divorce - top of page on 'Free Resources' menu. This will give you a straightforward overview of the legal and financial processes involved.
As to a 'fair' settlement, there are so many ffactors that fo to make up how it works, it is impossible to say what is fair without a lot of financial information.
You might like to try the Wikivorce
Divorce Calculator (Free Resources Menu) to give you an INDICATION of what might be fair.
Go take a look at the blogs, and maybe write your own, telling how you got to where you are. I found it helpful and theraputic. It gets the emotions out, and you can look back later and see how your thinking changes over time.
People here know exactly how you are feeling, and are ready to give you a helping hand if you need it. Try the chatroom to get to know a few of the people here. Always fun, but ready to listen and be serious when necessary.
Best of luck, be nice to yourself
Mike