Already Mentally Checked Out, How Do I Keep Going?

After almost 3 years of working for my current job, I am completely over it. It feels impossible to come in anymore because I know I'll be walking into an uncomfortable workplace. Catty drama, unsupportive boss, and mental antics.

Once you've already mentally checked out, how do you find the will to continue coming into your place of work? Or, if you work from home, find the will to keep showing up each day?

I've recently had two interviews for jobs I'm waiting to hear back from. Still applying for others but in the meantime, how do I get through my day without feeling totally drained from "keeping up appearances"?