I agree with everyone's suggestions above on how to reply, and the creative suggestions on how to deal with a crappy market and where you should live. Finding someone to rent the house while you live there could be a win-win, especially if they can cover most or all of your mortgage. But I'm not really familiar with what the housing market is like in the UK, so take that with a big, heaping grain of salt.
And I have to say, I hope you feel good about where you're at: to where you're exchanging these long e-mails and making progress on figuring out what to do with the house. This has come so far from where you were when he was almost non-communicative and everything was tense. You made that work, girl!
So, where are you going on holiday? I'm so jealous!!!
It is in the shelter of each other that people live.--Irish proverb