I agree with other posters that you need to take control of the situation @Febrilefrog543 and do wonder what his rationale was for buying a doer-upper in the first place? Do you mean you have been in your unfinished house for twenty years? If so, that's crazy!
We've bought a series of project houses over many years and have mostly DIYed them, partly for financial reasons and - primarily - because we enjoy it. Or rather, we did at the start - I'm now getting to the stage (in my fifties, seventh/eighth back-to-back project) when I'd much rather buy something already done. If only it was possible to find somewhere in budget done to our - fairly niche - style!
My OH can turn his hand to most things except complex electrics/heating and usually does, but I'm home all day whilst he's not and he definitely doesn't see the urgency in getting it all completed as I do, being surrounded by a building site! Our last place took six years, then we sold it straight away (because we hated the location, which had been his choice!) and I'm keen to not let our current project drag out as I want to start enjoying living here - which is difficult when everywhere is covered in a thick layer of building dust/piles of building materials/furniture.
Fortunately we did our bedroom first, so do have a sanctuary to escape to, plus we've an upstairs living room where we're currently camped out/eat meals etc - although that's a mixed blessing as it lessens the urgency to complete the downstairs imo. Currently we have no hot water and have had no working kitchen since February (new oven has been in the garage nine months), although we're seeing progress on that score at last.
Sometimes you have to put your foot down and/or set an ultimatum @Febrilefrog543 - I do, anyway - for example, we've been here a year next week and still don't have a working boiler (the one we inherited is 40+ years old and stopped working soon after completion). OH saw no mad rush to get it replaced as we'd just had a wood burner installed. He kept saying he'd arrange some gas safe engineers to quote for a new one, but as spring turned to summer with no progress, I took over and finally got a few quotes, stipulating it had to be done by end of Oct or I'd be moving somewhere warmer for the winter months! That got him motivated to do the plastering needed for the new boiler location and installation is now scheduled 😉