Monkeys never let go of a branch until they have a good grip of the next one they've swung to.
I agree that this has been going on for longer given his behaviour.
I was in your shoes in 2011. For sanity's sake you should consider a clean break settlement plus maintenance for DD / school fees (if relevant) etc. When you get the valuations tomorrow take a look on Rightmove at what you can buy for 50-60%. My XH was able to buy two nice detached houses in leafy Surrey out of one with an acceptable mortgage on his property so you may be pleasantly surprised at where you can live.
Your assets will be split based on what's disclosed by each of you in Form E and this includes all pensions. If he's a City boy then given his age he'll probably have a DB scheme too so make sure all of his pensions are disclosed for any pension sharing arrangements. See if you can find a Form E online to get a sense of what's coming. It's grim, it's not what you signed up for when you got married. I couldn't face the Form E for a year but you have your DD to get sorted and settled sooner rather than later. You have to play a terrible game of catch up in terms of detaching and all on fast forward.
During the bleakest of times when every fibre of me ached for the man that had been my H and my old life I used to repeat "detach detach detach" and bit by bit I did. I visualised our bond as a chain and slowly but surely each chain link broke until I really and truly didn't give a flying fuck about him.
I wrote my pain and anger away. I kept a pen and paper by the bed and spewed vengeance and bile onto that paper. When the time comes you might find that helps you to cope.
I also realised that I was not only dealing with XH but OW too. I knew him so well and the things he said, well, there were three of us in that divorce settlement so get moving before OW starts contributing.
In terms of DD has he mentioned seeing her when he's not modelling floral shirts and drainpipes in his London bachelor pad? Is he planning to pop down to the country and stay with you on his access days / weekends?
. That said DD might have other ideas given her age.
OP treat yourself as you would a friend. Do something special just for you every day even if you don't feel like it. Even if it's a candlelit bath it's something to remind you about who you were before you had dogs and chickens and a twunt to look after. One of the best bits of this awful process is rediscovering you. It's amazing what gets squashed when you're in a relationship.
Be kind to yourself. You've been amazing. 