I think the doubts you feel are normal; I still have them. The ups and downs, the doubt, the self-talk imagining yourself alone, all of it makes doubting good feelings natural.
The real question TJack might be what you want most - a marriage with her (assuming some change from both of you) or a divorce?
If you want a M the most, move only in that direction without any looking back. Make the full commitment and expect from her the same in time. Keep venting here instead of at her if you need to vent, see an IC for your own issues, and that kind of stuff.
My kids? Very confused. But, so am I. As a teacher, I think confused can leave kids worried, but hopeful. A divorce steals away that hope. If you think the kids are old enough, maybe talk it out with them and let them know you're trying and that you both need some mental space to work things out...so they need to see your school counsellor or whatever but not to look too deep into what is going on. Promise to keep them in the loop as things change.
The kind of M you want ("we fill complete physically, emotionally and spiritually") takes time, doesn't it?
One thing that helped for me was Retrouville. Maybe some weekend gig to respark your 'love bank' might help.
