Good for you!
And 51 isn't old, honey! Give yourself some kudos for courage!
You write like a man with intellect, a good education and clear
insight. Surely qualified for more than what you have been doing.
So treasure this time. Enjoy yourself and figure out what it is you want to do. If your friend won't support you, come back here. Looks like the
folks here think you are making a wise decision. Whatever you do
decide on, don't forget that you are bringing the invaluable asset of
a long, solid job history with you.
Maybe in a month or two you'll put your antiques and prints in storage
and join the Peace Corps or work on ranch in Montana or become a
tour guide at Stone Henge. One of my favorite jobs was working as a
recruiter at a fashion college in CA, and I truly just stumbled into it.
This could indeed be one of the great adventures of your life. Revel
in it. No doubt the universe is truly unfolding as it should.

Flower
__________________
"The life unexamined is not worth living." Plato
"The arc of the universe is long but it bends toward justice." Dr. Martin Luther King

To Bambi, "You can call me Flower if you want to."