I call that black ice because it doesn’t show....I took a long slide down the hill one night in my car and was very grateful for a curb just before it was time to go up the hill near my home...That ice had had formed while I was big grocery shopping. No harm done and no other cars around.
I know that fall was painful that you had.
It was a week ago and still hurts.
My niece gave me some heating pads which might be helpful.
Thank God you are OK...black ice is scary!