Resulting symptoms of sudden stoppage of 50 years of diazepam usage?

There is help. There are physicians who will help you come off slowly. I am so sorry you are suffering.
Here are a few references:
Try The Ashton Manual. It is online and it is free. It is considered to be the gold standard on getting off benzodiazapines.
check out benzobuddies support group and ask for a link to physicians who will do this slowly. Hoping this will work for you and am so sorry for what you are going through.

There really is not anything that truly helps with anxiety other than benzodiazepines and doctors are slowly but surely getting away from prescribing them. If you have an old doctor you may get them for a while. If your doctor dies or retires and all you can find is a younger doctor you’ll probably be out of luck. The doctors are prescribing antipsychotics off label, antidepressants exclusively or beta blockers off label. There really isn’t anything else out there.

I’m not finding that to be true. Both my primary physician and my psychiatrist who are both relatively young (40’s) are happy to prescribe me anything that is medically necessary. This includes Ativan. I think that rgtaylor shouldn’t give up. There’s someone out there who will be willing to prescribe you whatever is medically necessary. And I think some kind of Benzodiazepine is for you.

Doctors are still prescribing them.
and there are doctors who specialize in very slow withdrawal.
Here is a book online/free that is considered to be the gold standard. It is "The Ashton Manual". I cannot link yet as I am new.
Best of luck to you.
"The Ashton Manual. The Ashton Manual, written by the late psychopharmacologist Heather Ashton, presents the most well-known and respected withdrawal method in the benzodiazepine community. Dr. Ashton ran a benzodiazepine-withdrawal clinic in the U.K. for fourteen years, which reported a 90% success rate."