faiefuff - brutal, but spot on really. Although i tend to think there may be a little more hope than you suggest.
Firstly, staying together for the children is a recipe for disaster OP. You've mentioned how you may have handled things diferently 'pre DC' a couple of times now. Children do pick up on the machinations of their parents relationships even if you're doing your level best to cover them up. You may think ''as long as their lives carry on on a good even keel and they are not seeing us rowing then everything will be fine. I/we are adults and clever enough to make sure they are none the wiser''. This is fantasy, sadly. So perhaps try to put 'staying for the children' out of your mind while you think about what to do for the best.
I still see the split as worse than the staying together. We would not know that for sure though until both had happened and we compared
- few people relish a split. But i think you know the time is right when
a) you can admit to yourself that the relationship is making you (both?) miserable long term, and the thoughts of jumping through hoops to put things right feels like too much effort. You only get one life. You're entitled to find a way to make that happen, moving forward responsibly and kindly as you can, for both of your sakes.
- and/or b) - there are kids involved who may being damaged by seeing an unhappy set of parents.
It might feel as if you've gone from a fairly simple question about kissing to discussing divorce here on your thread, but, as you say yourself, it's obvious the kissing issue is just a tiny tip of an ice-burg. To talk about the kissing and even the sex, tbh, at the moment, seems to me to be like shinning a torch into the Grand Canyon at night and be trying to work out the whole picture.
Your DW has effectively shut herself off from you, physically and mentally.
Re: the physical side of things, i'm finding it odd that you say this could well be the way the DW is. I feel you should know, y'know?!