My method of staying sane is way less complicated.
I am not unique or special. I am human. Ergo things that keep humans sane should work on me.
So I read up on mental health and then did those things. Sleep, nutrition, exercise, sunshine, make friends, community service, clean air.
It’s likely I may still experience issues later in life. But all life is always temporary. It’s about the now, appreciating this moment when I have a dog beside me and a snoring spouse and a wool blanket and a nice book.
I can only control what I can control.
I’m learning rock carving. Rocks are awesome and last through lots of disasters.
The worst case scenario, of course, is a system enforcing an absolute lack of privacy, when that system is owned by an enforcement agency which is not dedicated to any true prosocial goals, but to the continuation of its own power structure. And that’s the end state of all surveillance and power structures because that’s where the motivation and feedback reward loops trend. Anything which does NOT enforce its own monopoly on power is overtaken by things which DO enforce their own monopoly on power. The has nothing to do with the advancement of humanity or science or anything like that—we could easily end up in a very stable, very stagnant worldwide society of dictatorships which do not promote growth in any meaningful fashion because the mechanisms of enforcing control have been perfected and the need to enforce control remains the top priority and survival strategy, well over any other goals.
The more power you have, the more you can enforce your monopoly, the more incentive you have to enforce your monopoly. Consolidation of power occurs and at the top levels, and then high level echo chambers drive antisocial, anti-humanistic behavior with no consequences.
Congratulations, you’ve invented something worse than “I have no mouth and I must scream”: the perfect private torture chamber for an all powerful cadre of the worst humanity has to offer.
Most people will be mostly fine, of course. Even massively corrupt abusive slave owning states usually manage to ensure some sort of reproduction and survival threshold, and people can adapt to almost anything—read some North Korean escapee stories with the understanding that most people in North Korea are, in fact, happy most of the time, even if they have zero effective freedom or control over their destiny. The people who escape were people who were unhappy enough to try. Not everyone wants out.
Also, understand that you—the reader here—will likely not be part of the owning class in any such state. Everyone imagines some way in which they will hack the system, in much the same way that in the heights of the memory regression fad everyone was telling stories about being royalty in a past life. You will at best be a valued worker for a little while, in so far as you are willing to utterly subsume your ethics, morals, code of conduct, and personal identity to that of whatever owns you.
Studying the worst of historic fascist dictatorships and slave states with an eye towards the behaviour of the owned folks is a nice way of seeing the survival strategies which might work for you in the future, so you can extrapolate a bit for ways to retain scraps of your personal independence and dignity. For example, if you’ve the resources for it, it might someday be useful to consider botox for facial paralysis to prevent cameras from inferring anything about your thoughts. :)