@Debutante - it sounds as though you have a lot of thinking to do and some potentially difficult conversations to have with your husband. People on here have shared some relevant experiences and given sound advice. I would just say before making any drastic decisions or big jumps please explore as many of your options as possible. Try categorising things that are important to you and researching each - writing lists so you can see things in black & white. For example:
1A: What options do you have in continuing to share a home?
1B: Where might you live otherwise and how much would it cost?
1C: How would co-residency work? How would finances work? Chores? New relationships (this could be a BIG problems for either or both of you). Even having friends visit, especially mutual friends.
2A: Look at your current financial situation and how this could change
2B: If you did move out or rent are you entitled to any benefits? Or would you husband move out? If so, could either of you afford to stay in your current residence?
3A: Is it worth talking to your children? For all you know they may be more aware of the cracks in your relationship and be keen for each of their parents to be happy even if not together. They may also encourage you to use any monies/savings to sort your own lives out rather than see it as their inheritance - they may be more than happy to make their own way in life with their own resources.
4A: Are you currently working, or in good health enough to gain employment? If you are unwell would you be entitled to any relevant benefits or help?
For what it's worth, to answer the question at the close of your post....about 35+ years ago (before my current long-term relationship) I was sharing a 2-bed flat with my previous partner, we split up, I bought new bedroom furniture and moved into the 2nd bedroom. It didn't even last a month, probably a week or two ...he left. He had been in a higher paid job than me but couldn't afford the flat on his own so left me with that + his debts. I had my health back then so got a job that paid more than his and stayed put. I had to work a full-time job + 3 evenings a week + any weekend work, conferences, workshops etc I could pick up. It was bloody hard but rewarding, and I was so busy it stopped me from dwelling too much on the failed relationship. In hindsight I should've known sharing a small flat would be a nightmare and looking back makes me glad I made the choice to better myself, my income, my standard of living etc. My health these days would close those options to me so please look at all aspects and make the best choices you can now, while you can. Good luck whatever you decide to do - I wish you all the best for a happier future.