One other thing that is great for your mental health in any job, is treating it as a job and nothing else. Something you do for 40h per week to get a salary to pay your bills.

You're not there to make the world a better place, to belong to a family, to improve anything. Just do your job and go back to your life at the end of the day. When you're off work, do your best to forget about it. In fact, always prepare yourself for interviews, so leaving your current job it is easier when the time comes, and it always comes.

This detachment always served as protection from toxic workplaces, and I worked in a few of them. Don't let anyone fool you that it will harm your career, the only thing that will harm your career is not putting effort to learn skills that are in demand.