I haven’t been through what your husband has been through but I and my wife have been through family-created financial burdens (and crises and disasters and flaming garbage fires of financial recklessness resulting in police hammering on the door in the wee hours of the morning) - so the financial burden hanging around your necks is one that I understand.
Money and property and the debt that can be connected to them is a tremendous psychological burden on a relationship, both one’s relationship with oneself, and one’s relationship with one’s spouse and children. It preoccupies and it tends to amplify whatever tendencies are already there, whether it’s a tendency to withdraw (as your husband may be showing here; depression is many things but withdrawal and retreat is one of them), or a tendency to act out / be reckless, or any other behavioural tendency.
Having recently purchased a business I know the feeling of making a major financial decision like that. I considered three options for my purchase, two which had existing customer bases and revenue streams and one which was just starting and had no market presence (the business is a good concept and there is a demand, it’s just this particular brand has no presence here - yet!). Ultimately I went with the third option because it was the cheapest by far, which has given us financial breathing room and helped us ride some waves over the summer.
It sounds like you guys are carrying a heavy financial burden and that is weighing your husband down, and when he’s weighed down it tends to weigh everyone down (such is marriage 
).
My first question would be, is there anything you can do about renting some of that land out to generate additional income? My wife and I rent rooms which helps us pay the bills while I’m starting up the business.
My second question would be, are there any solid options for online therapy? There is BetterHelp of course though I’ve heard it can be a bit mixed in terms of quality. My wife does her therapy with a private counsellor online. She got a referral to this person a year ago and it was random but they made a really good connection and she’s kept it up. I have to imagine searching for someone would really help your husband. It’s possible he may not connect with a couple but he’s bound to find someone that works.
I have depression too. I had some days I could barely get out of bed in the morning; I often had dark, discouraging thoughts. I spoke with my doctor who did some mental health assessments for me and prescribed me some medication. That medication has made a huuuge difference. Huge. Obviously it’s not some magic thing that I don’t have to do anything else - I still do therapy, we do marriage counselling (keeping ourselves in top form!), I still have to get to work daily, I still have to (and I do enjoy!) be an attentive spouse - but it has changed my mood and made it so much clearer, helping me to stand on my own two feet, to be present for myself and for others.
Once those concrete things are dealt with - which is essential for him, to be clear and to see things clearly - he can start digging into what draws him to this image of himself as a farmer. It’s never about the physical; the physical world always symbolizes something to us, it always means something about our core beliefs and our core identities. (This is why my wife and I arguing about the dishwasher is never really about the dishwasher.) When he’s in a position where he (and both you guys) are standing on your feet with some mental / emotional clarity and some clarity about cash flow, it’ll be possible to dig into some of that and help him get grounded in his inner currents. This will help him (and you) to talk openly and constructively about where the currents of your lives are going.
It’s a hard situation you’re in, I know. It is high-pressure. Pressure breaks rocks but it also makes diamonds. Your goal is to be the diamond. I promise you it is possible. You will have to dig deep, emotionally, deeper than you can even imagine. You can do it. It is hard but you can do it.
