Haven't read the whole thread yet but I am totally with your husband. And I speak as someone who knows how difficult driving is.
I had my first driving lessons in my third year at university (so 2006/2007). Before that I was too afraid.
Unfortunately I changed university for my master's and had only had six months' lessons by that point, so wasn't ready for a test. After a six-month break from lessons I had another six-month stint of lessons in my university town. Took a test and failed it about as badly as it's possible to fail without crashing. This was in 2008.
I then moved abroad. What with moving to a new country, getting my first graduate job, moving apartment twice and changing jobs once in the space of six months or so...I didn't get round to thinking about driving lessons again for some time.
Fast forward then to September 2011. As mentioned I was living abroad - specifically in France. In France they don't allow you to take any practical lessons before you have passed your theory - which I find very silly. So at least in the UK you have that on your side: you can put your theoretical knowledge into practice immediately. Like you, I find it very difficult to visualise things, so found it tricky to not be able to do this. The French theory test is also very different in content and approach to the British one, so because of this, I didn't pass my theory test in France until July 2012.
Everything in France shuts down for the summer, so I didn't start practical lessons until September 2012. In my mind, I still knew how to drive (though how I thought this would be the reality given that I hadn't actually driven for four years, I had no idea), so thought it would just be a case of brushing up on my (even I knew rusty) knowledge and signing up for the practical test asap. In reality I had actually forgotten how to drive and developed a full-blown phobia of driving. It took many months of lessons and I did many a manoeuvre with tears streaming down my face before I was even halfway ready to take a test, which I did for the first time in France in October 2013. (I still dissolved into tears halfway through so clearly was not that ready.)
In France you cannot enter yourself for the practical test - only your driving school can. There are limited slots and in the Paris area it is even worse. So by the time you are on your second or third attempt (as I was) you are a low priority and can be left waiting months or years for slots. My next test was therefore not until May 2014, which I failed on a technicality (having luckily overcome my phobia).
At this time French driving schools could still charge €100 to transfer your file to another driving school (even to one I could walk to in about 10 minutes). This legal loophole was thankfully then closed so in November 2014 I sent my file to a driving school in the south of France where my aunt and uncle live.
In my holiday I travelled there, had two hours of driving lessons on the Monday and the same again on the Tuesday before doing my test on the Wednesday, which I passed, finally getting my licence in February 2015.
I tell you all of this to show you that if I can do it then anybody can. I was phobic of driving, had/have coordination and spatial issues, and was having to do the majority of this in my second language, in the face of the frustrating bureaucracy of the country in which I chose to live. I'm guessing you maybe only face half of these issues.
So perhaps you are now wondering why I think your husband is reasonable, and why I pursued all of this despite my difficulties.
I am, and have been, lucky enough to live in places where public transport is excellent and essentials (e.g. supermarket, pharmacy etc) and luxuries (e.g. restaurants) are in walking distance. So you could argue that I did not need to put myself through all of this.
However, I know that I may not always be this lucky. You never know where you might live in future. In your case, you actively wish to move to the countryside. Others have already pointed out the deficiencies of public transport in these areas of the UK.
I do think it is indeed more practical to be able to drive when you have children.
I also wished never to turn out like my grandmother, who has never learned to drive. Now that her husband has died, she has to get a taxi to the supermarket once a week, and pleasures that she once enjoyed (e.g. holidays to Scarborough, trips to the theatre) have now been eliminated. When he was alive she was forced to be his passenger even when he was over the drink-drive limit. Why would you ever want to put yourself in either of those positions? Considering what the future may hold does not just encompass places to live, but a whole range of other situations.
Even today, the independence driving has already provided me with is invaluable and I am able to help my husband with the long-distance driving that we are at times obliged to do (living in Holland and having family in France and the UK means being able to drive to visit them can be greatly advantageous!). You can also go to far more places on your holidays that are off the beaten track, rather than being restricted to the tourist trails, if you are able to drive.
I hope this provides some impetus to motivate you to take up driving lessons again. I know what it is like to be afraid of driving and that you will be terrible at it. You just have to remember that the benefits far outweigh your fears - and that many people far stupider than you have managed to learn how to do it before you!