I'm very sorry to hear about your struggle. It sounds like you have tried, but he hasn't made an effort to make the marriage work. Maybe he can't. He needs to find a new lease on life, but at 82 it can be very hard. I wish there was a graceful way you could get out of that marriage and be with someone who can make you happy. Life is very sad that way.
My sister is in a similar situation with a man who just completely lost interest in her, and now she lives alone in Georgia where she teaches at the University, even though they're technically still "married". He still lives in the house they shared in Norfolk, Va.
The job market is a whole other story. Age discrimination is a big problem, but I'd like to convince myself it's getting better. Where I work there are a lot of people in their 40s, 50s and some 60s. At 57 I still get hits on my LinkedIn account, and I got two job offers within a month after I got laid off at 48. Also, my sister got her PhD and landed a professor job in her mid 50s. So there is evidence, at least anecdotally, that age discrimination is at least abaiting, if not reversing itself, in this country. Remember that the "baby boom" generation comprises a vast number of people and a huge chunk of the population, and there is strengh and voice in numbers. At the very least maybe lawmakers will start making policies that will favor hiring us.
I say these things to comfort myself as well as give hope to others who are reaching these age milestones.
Like Abraham Lincoln once said, "You can't believe everything you read on the Internet."