I am happy to offer my opinion but be aware there are people more emotional intelligent then me here. I believe honesty is the best policy. These are the points I would stress to my wife in your situation.
1) The marriage is broken and needs a major overhaul. 2) I need to work on myself to be the best me possible, for me and for my spouse. 3) You need to work on yourself to be the best possible you, for yourself and your spouse. 4) After we have made constructive repairs to ourselves we can begin to repair the marriage. 5) I will begin working on myself now. 6) You must begin working on yourself. 7) I will not remain in a broken marriage.
That's the direction I would go. You could word it much better I'm sure. It says your in, but not forever.
