I'll focus on my CS major, even when I'll probably be over 40 when I finish (due to the several next crisis along the road).
In my last job, I found great joy in reverse engineering (interoperability with a quarter-century proprietary legacy system). I also find cryptography and cryptanalysis amusing (applied abstract algebra is nice).
I would like to focus on that career path. Job openings involving those areas are mostly security-related.
But I fear a possible toxicity in that adversarial role (i.e., last line of defense against a whole industry of malware and malicious actors). I can only imagine future burnouts and extended anxiety while dealing with the ever-increasing work demands.
How realistic is that gloomy scenario in InfoSec?
P.S. Cryptopals [1] and Dennis Yurichev's reverse engineering challenges [2] seem quite reasonable for practicing/learning.
There are plenty of Capture-the-Flag, Crackme, wargames, programming challenges, etc., but initially I'll do these.