Hi and sorry you're in this boat. I'm a LBW with in-home separation going on just about a year now. While there are some specifics to my situation that vary from yours to make mine the way it is, I can speak a little about the points you brought up.
I can give you the W side of the family bed issue. We did the same. We did not research it and decide - yes - we want to have our babies in our bed for the next nine years. But it just kind of happened. We loved being with them all the time, especially me. I nursed mine in bed so we didn't have to wake up, and they slept with us much of the time. They had their own beds and so they weren't entirely in ours, and we did manage to find time to ML. A lot of couples swear by Saturday morning cartoons. But there is an emotional toll that it takes if you don't work at staying connected. My kids are now 12 and 14. My 14yo almost never sleeps with us, but if he's stressed out or misses the dog that also sleeps with us, we'll sometimes find him wrapped up around the dog between our feet in the morning. My S12 is more cuddly and less independent, and he'll fall asleep watching tv with us, or want to be in our bed more often than his brother, but for the most part they've both grown out of really sleeping with us, and they are fine with us kicking them out. So I do not think you're weird for having a 6 and 9 year old in your bed.
I do think that you need to recognize, with your W, that it would be better for them and you to get them used to being in beds of their own now. It wasn't a problem before, but now you two have some issues you need to work out, and this can help. Have that conversation.
I'm so glad you didn't move out when you got the bomb. Based on what you described, and the things she said she wants, it doesn't sound like she is set on divorcing you. My advice would be follow the rules as much as you can - don't pursue her, work on you, GAL, be a man anyone would be a fool to leave. Do more of what works and less of what doesn't. Find out more, if you can, of what's gone wrong and work like heck on it. Do not bargain and tell her that she needs to work on herself too, or blame her, or make excuses. If you need to fix something in yourself just do it with no expectations of her. That's attractive. Pointing the finger back at her is not, and it's premature right now.
If she recognizes the possibility that things can get better, she'll possibly decide to work on her half of the stuff too, but don't think about that. Just fix you.
I would suggest that you read Five Love Languages and see if any of that resonates. If your partner doesn't know how or is not willing to fill your 'love tank' with the things that are meaning ful to you, you lose your connection and attraction to your partner. Start filling the tank again. It's possible with the co-sleeping that she loves physical closeness. If you try a nonsexual hug or brief shoulder massage when you pass by, would you get a pleased response or a recoil?
Also, if she's interested in working on things, you might look for Retrouvaille workshops, as many on these boards have said they can help restore the connection. I'm looking at them myself, although my situation is pretty far gone.
I hope that your bomb turns out to have been more of a warning notice. I'll follow along, hope you keep posting.
Adinva 51, S20, S18 M24 total 6/15/11-12/1/12 From IDLY to H moving out 9/15/15-3/7/17 From negotiating SA to final D at age 50 5/8/17-now: New relationship with an old friend __ Happiness is a warm puppy.