Hi, I’m a retired chess teacher (best ELO 2390.)
Korchnoi was still world-class at 60 and ranked in the top 100 at 70.
As peccavi said, you’re limiting yourself - there is a lot of chess knowledge in books.
Absolutely - you learn a lot from reviewing, especially with your opponent.
I’ve posted before here on improving at chess - have a look at post 6 in this thread:
Please recommend a path to learning chess - The Game Room - Straight Dope Message Board