Lots of good advice here already:
Life Insurance, if he should die, usually should be written in simple trust so it doesn’t get held up by any bigger Estate process.
Life insurance for you probably doesn’t need to be as high as you need if he dies.
Critical Illness insurance if you can afford it.
Income Protection plan - is there any insurance if he is unable to work through illness or injury
NFU could be helpful for the above but a general financial adviser could easily help you navigate this and do all the forms.
A Will for him is mission critical if one doesn’t currently exist that favours you. Solicitor, ideally not the one who advises the PIL, but who does have adequate knowledge of farms and land - someone else suggested a Land & Estates specialist or words to that effect. Farms and all the ownership stuff can be tricky if working blind so you might have to use existing solicitor who knows the set up.
Power of Attorney - no one has mentioned- also important if he owns loads of land. If he was alive but unable to manage the land in his name, through major illness or injury - you need POA for him. Solicitor is critical to help navigate this.
it’s not a terrible suggestion either, if he owns the land, that it could be changed to joint ownership with you but that’s also something to take advice on to cover all relevant aspects.
otherwise saving money in your own name or joint names and/or buying a property off the farm but that might not be affordable at this time.
it’s great he is on your side - if he sees how toxic the PIL are to you he will hopefully be on board for necessary meetings etc. Farms and farmers do work in a realm outside of the norm in my experience but much of the advice above is generally good for anyone with children or where the asset base is tricky and/or not in joint names already. What do you really know about land? What land is it? Is it surrounded by other land he doesn’t own which essentially limits who could do what in practice? (I’m not actually expecting answers I’m asking you what you know properly for yourself so that you are informed)
You’ve potentially got a lot on the to-do list but you could also potentially achieve a lot in a short space of time if he’s on board and you get to financial adviser and solicitor pronto, and have massive peace of mind that you know what’s what and have control of the bits you can control.
Best of luck with it all.