Pool is insanely. subtly, insidiously difficult to play well at a steady level & we just don't realize it when young.
When i started back a few years ago it shocked me that it in no way relates to that old chestnut "like riding a bike - you never forget" (related to many activities). Pool is not like that. You think you know and it all goes wrong for many of us, pretty much without daily practice. Which is easy to forget - some of us were playing 3 nights a week minimum, often 5 or even 7. Every week. For 6 - 8 hours a session. Now i go back & hope to play that way when i show up only once a week for league, or maybe twice a week if it is league and the tournament. & get punished badly most events.
Funny thing is, at 68, i decided to try skiing again this past winter, had not done that for 12 or maybe 15 years. It was embarrassing, humiliating, frustrating the first couple times. But after 6 or 8 days out, i realized i was skiing better than i ever had in my life. (partly a reflection of realizing through online videos how bad my technique was in the old days) Can't do the bumps well anymore, scared to jump much, legs won't move fast enough and one run of that will just about exhaust me for the day. But as far as control, and even a bit of finesse, i can ski slopes smoothly that intimidated me when i was younger and stronger. Being willing to slow down, and figure out how to use technique where strength allowed my really bad habits to get by in the old days.
Back at the pool table, it is up and down, mostly down worse than on the ski slopes.
Told my wife i am really not enjoying this league session (flex singles). Not because i am losing, but because i can't figure out any consistent way to get better. Even with practice. even watching videos to develop good habits. They evaporate without daily use because so many are eye and brain orientation that to me is essentially pool focused in ways that are not essential or are even counterproductive to daily use. (laser focus blotting out surroundings, almost a trance state when "in stroke")
Take-away: hopefully there are other things in your life that are still satisfying & let you feel more or less competent.
There are at least several in my life i am very grateful for.
smt