"Unfortunately I discovered audiobooks and podcasts,"

As an experiment, mess around with the subject. I'm about 10-15 years further along the path than you by description. I found that liberal arts / history / pretty much any lecture series from "the teaching company" really cleared my brain and gave me things to think about.

On the other hand trying to listen to "tech" stuff just turned into an extension of work, drained more than recharged. Nothing wrong with that stuff while puttering around or doing yardwork, but it didn't recharge me like doing something "new".

So do some A/B testing like this:

Podcasts : "Software Engineering Radio" "The Linux Link Tech Show"

vs

Podcasts : "The History of Rome by Mike Duncan" "In our time with Melvyn Bragg" "Dan Carlin's Hard Core History"

Now see which "group" of media clears and refreshes your mind better. Takes you off task, lets the unconscious cook for awhile. New ideas sprout to the surface. Comparisons and Contrasts and historical analogies...