Oh love, I'd be livid too. He gets to stay in the house with your son, decide when it's sold, and you're meant to sleep on a mate's sofa and be grateful? No chance.
Please don't move out until you've got something agreed in writing. Moving out doesn't mean you lose your share of the house, but once you've gone it's very easy for "6 months or so" to turn into a year or two, and he's the one calling the shots.
If the house is only in his name, look up registering "home rights" with the Land Registry. It's free and means he can't sell or remortgage behind your back. And whatever you two agree, get it made into a consent order. Otherwise it's not really binding, even after the divorce goes through.
Also 50/50 isn't a given. They look at what you both actually need to rehouse yourselves, so if £80k won't get you somewhere, that counts.
I actually work on a site called divorcd.com that goes through all this step by step, the house stuff especially. Might be worth a look before you speak to him again. But honestly, a free first call with a family solicitor would be money well spent too.
Hope you're ok xx