Jeff, maybe this will jumpstart you. Ladies, feel free to jump in and critique. It was written quickly. I will not be offended at all. Just trying to throw some ideas around for our friend, Jeff.

I am writing this letter to you because I want to be sure that I am able to say everything I have been feeling. So here goes. We have not been happy in this marriage for a long time. And while I know we are getting through the days, I want more. I have to know if you do too.

We have a history together, you and I. And four wonderful children. And in this uncertain world, that is more than most.
I would like for us to give this marriage a real chance - to see if we could find happiness with each other again.

I need to know if there is any chance that you would like to explore what our future holds.