The best way to deal with a truly toxic work environment is to leave. However, there will most certainly be situations where you are not able to leave the job at least not immediately. I have tried the tips below to survive the jobs I was no longer enjoying. I was overworked and often low on energy, someone helped me talk through it and we created this strategy.
1- Take something to work that serves as a visual cue to something positive. A picture of your pet, spouse or family, pack a nice water bottle, or a desk calendar with positive images or messages.
2- Leave as often as possible. Take your breaks and lunch. Try to step outside for a walk. Even just for 5 minutes.
3- Breathing exercises. Nothing is more powerful than learning to control your temper with breath work.
4- Find something to look forward to at the end of that day that is healthy. I signed up for yoga classes. It could be gym time, a nice walk, or a cup of warm tea with a book when you go home.
5- Schedule in your job search time
6- Learn something online
Remind yourself that you cannot let a place change you. That you will get out.