Speaking from experience, burnout is not something that can be fixed overnight. If you are being overworked, which it sounds like you are, then you need to scale back the work you are actually doing dramatically, and spend focus time on your own mental health.
If you find you are unable to still your thoughts after leaving work, you may find meditation useful. Not many people give a good explanation of meditation, but the gist is it is practice in stilling your thoughts and emptying your head of unnecessary and unproductive distractions. You can do it just about anywhere fairly simply with a candle and knowing a few simple visualizations at first and all it takes is 5-15 minutes. The visualizations are only necessary if you can't calm and still the thoughts, sounds, or pictures popping into your head. It gives you something to focus on and distract until you can get it done. Its a valuable coping mechanism for high stress environments.
You have a choice to either do this fixing by scaling back, or you spend 3-6 months unpaid recovering when you can no longer manage, and that's a best case scenario. If you find yourself becoming agitated or terse from the smallest of issues with your co-workers, you are likely at stage 3 which is just prior to complete meltdown. Its not like there's a clock on this, but there is always some event that starts the ball rolling, and you then melt down under the stress of it. Its not predictable, other than it will happen eventually.
Its important in any IT job to have a good work life balance. It sounds like that is messed up right now and your employer has indicated they don't care because they've taken no steps to mitigate or fix the underlying issue. They are exploiting your ability and productivity at the expense of your health.
Many IT workers that are unable to moderate their activities end up quitting eventually after the stress has taken a toll on their life. For instance, High Blood Pressure, Weight Gain, Diabetes, Sleep Apnea, Heart Disease and stroke are not uncommon challenges if you ignore and just self-medicate.
In case I didn't make it clear, there is no solution to prevent burnout. Burnout happens when you work harder longer than you should. If you are not self-moderating, then you will burn out.
Moderating includes not working off the clock, not being on-call without a rotation, not thinking about work off the clock (at all), not doing anything work related outside your normal hours, and scaling back the work you do while on the clock to the bare minimum of what's expected for any other role of the same type.
This also mean's not setting up perfectly resilient automation that needs no interaction because they'll just fire you after your done.
While they may say during the hiring for that; the wages they pay must be in line with that kind of work for you to do that work. If you are eliminating your own job or another's job, there must be additional compensation close to the cost of the labor savings to account for the work you won't have after the job is done (because they will let you go), basic market forces.
Don't believe me or agree with that? Go and read The Wealth of Nations 1778 by John Adams, it covers factors of markets, supply and demand, including that for work that is intermittent and how wages must be adjusted to account for basic fundamental principles which employers have conveniently forgotten.
Not everything there holds true now because of monopoly and debt/currency ponzi, for instance its now possible to force wages under what people once considered the fundamental lower limit on wages which included the cost of raising 4 children so that one would survive to 18. You can thank easy access to debt ponzi for that. Today, with the greater risks and intermittent modern medical technology, 2-3 children are needed. The 30-40% increase they reported in "All deaths" actuarial information is most likely attributed to modern medical activities and checkups being severely degraded during the pandemic, prior to that 1-2 was acceptable to prevent depopulation from a growth perspective.
The aspects within that book are generally what was known and accepted for centuries before the shell games and manipulations we see today. The chapters are fairly short unlike modern books today.
While every person has their own idea of what wages should be, a good medium for the latter case is average wage for your position at a non-startup x 5 years for that kind of work (The work of automation and role removal). If they aren't paying you that, they are explloiting you for work they should be paying more. The book is a very important read for anyone.