beigeish, I am sorry you are in such a tough situation. I really think you are thinking along lines that make sense to me. Keep the job and deal with the situation the best you can.

I worked a stressful job for a long time. It was a grind but I set up a series of routines that helped me. Not sure what routines would help you but here is what worked for me.

Mindfulness following my breath and restoring some calm to start the day
High protein low carb breakfast so I have enough energy to get through till mid morning
Do exercises to lower stress levels either before leaving for work or after arriving at work early because of traffic
Get to work 15 minutes early so I do not feel stressed starting work and gives me time to plan my day and the next few days.
Mid morning, have plain yogurt, tofu or some kind of high protein low carb snack. Helps me get over that anxiety that arises from deadlines.
Lunch high protein low carb lunch AWAY from my desk and preferably out of office.
Nap in car 20 minutes. Set loud alarms so do not sleep too long. If not nap just relax in the car and get away from office.
Mid afternoon, another snack like in the morning
Try to go home at or near official end of day. I can only do so much.
Good supper when I get home.
Something fun or relaxing.
Before sleeping have 15 minutes of quiet time and try to be present and not thinking about work.
Get 8 hours of sleep or as much as possible to relieve stress and anxiety

It was all about finding a way that I could survive harsh conditions and inconsiderate people. I had to get back some of the control of my life and the routine helped me do that.

Another part of my routine was to follow my heart's secret longing on weekends after I did the shopping and stuff.

There are no magic wands but coping with the situation and having income may be preferable over quitting and not knowing where the rent is coming from.

A therapist helped too. All the best to you in finding the things that help keep you from sinking into the mire of work.