When things got kinda out of control and we feel somewhat demoralised, there are few things that we can do to alleviate the work-related stress:

1. Learn how to say no

People simply don't care whether you have finished your current work or not. They will simply prefer someone else to do their job especially if that someone else is willing to do so. The incoming flow of jobs will totally overburden our brain so learning to say no is probably a way of survival. Although, the management will be more likely to use this against you during the performance review under the pretext "this staff refused work". Well, sanity or career advancement, you probably have to know yourself well before deciding. More work? No, thank you. 

2. Do fun stuff outside office hour

If you can't wait to break out of the 8 hours of being chained, you can do some other fun stuffs like an exercise at the gym, an evening walk or a leisure jog. These kind of activities are not only healthy but also able to help you release some steam. If you are not the active type, you can do some reading, shopping, or bitching with some friends (trusted ones I hope).