First - the opening White had played was quite popular during the 1950's.
I guess White intuitive gave up Pawn on "c2".
What does computer say about 18... d5?! I know I would have played in a Blitz.
Probably bad because
Qe2 and so on...
21. Ne4! must be stronger than Re3.
Knight ending was attractive, Black would still have advantage even if Black didn't play 23.Ng5.
If it was OTB game, both of you should be proud of it.