Could you partition the property?
First, try wallowing in self-pity. Then if that doesn’t work, follow the drink-weed-drink method. Lather, rinse, and repeat as necessary until you can move on to whores and cocaine. Make sure to keep drinking.
If he can’t come up with the money you don’t really have anything to feel bad over. It’s your fair share to do with as you please.
So it’s either give it to him (which is what “payments” would be as you know already) or don’t give it to him.
He will likely get over it in time. Until then you can’t change the situation, so don’t worry about what you can’t change.
You offered the property to your brother. He did not accept your terms. He even claimed they were not market terms, but too high. You now have an offer from a third party, I assume at your same or near same terms. This means that your brother was wrong about the market value of the property, and you should be free to do whatever you wish with your property.
Best of luck. You may not want to mention anything about the neighbors to your buyers. Although, I’m sure that your brother may do everything he can to scare them off.
Distance can help, too. Although it looks like you have at least 45 minutes worth of that. Any mental distance that you can add will help, too.
It’s hard to get that distance while he’s making everything more painful for you. What he’s doing is making excuses for why he’s lost a property that he planned to make his. You did not lose him that property. Even if it’s loss is painful to him, he has no excuse for attacking you.
I hope that the sale will go through quickly, with no big snags. I hope that the people he’s venting to know him well enough to recognize that’s what he’s doing. I hope the pain passes.