OP is this really what you want?
Or is this an ego thing seeing he has moved on "quickly.
You list only practical things for the reasons of you wanting to remain in the marriage, yet no mention of your DH ex qualities, and that you miss him. That is telling. Also, having an emotional affair, he is unlikely to ever trust you again, also because you ended it. Going back is a huge risk for him.
If you do go back it will never be the same relationship but a new one. Is he likely to entertain the idea?
Also, you cut your losses with him, he find someone else, now you see he is happy again and want to attempt to sabotage that for him as well.
What is it you can offer him now that you could not before?
Why should he consider it?
If you are completely honest with yourself on the reasons, picture yourself sitting him down and have that honest conversation with him, about how you feel about him, because it has to be the reason, him, not the house or the DC, or how long you two were together or the financial impact.
The reason he has moved on so quickly is because you discarded of your marriage, opted out, emotionally invested in someone else, who may not be in the picture anymore, so now your focus is fear of going solo, regret and panic.
Not good enough reasons to go back, work on you and the reasons you felt your marriage was no longer it for you.