I've had to think about exactly the same issues - like you, I had a fair bit of OO when I was a kid in the eighties. As far as I can tell, the things you need to think about are:
Space - N gauge allows you to run very long trains in much smaller spaces, and as has been mentioned, you won't get far in OO in the space you have, which is a major incentive to consider N.
Availability of stock - it's improved in recent years, but N still has a smaller range of models in it than OO. Do you have a particular era/location you'd like to model? It may be that you're itching to own a model that's only available in OO, so that might be a deal-breaker. There's also FAR more secondhand stuff available in OO.
Quality - Older N gauge models were pretty dreadful, and not as good as their OO counterparts, but I'd say that's much less of an issue now, and not worth worrying about if you're buying new.
Durability - N is undoubtedly less robust and easier to break, but both scales can be fiddly and tricky - an issue to consider with your dyspraxia, but I very rarely broke anything in OO, even when I was five and extremely clumsy.
DCC - if you want to go digital, it's generally easier to install chips in OO locos, although DCC in N is perfectly possible and plenty of people do it.
Price - more or less the same for many models in OO and N, but some N gauge models can be more expensive, and as I said, rather less is available on the secondhand market. Maybe an issue if you're on a budget. As someone used to the somewhat cruder Hornby models of the seventies and eighties, I find the cost of modern models in both scales somewhat horrifying.
If I were you, I'd say the space issue is about the biggest, and that would veer me towards N. I've got a garage, so when I finally get around to clearing the space, I suspect I'll go for OO.