A colorful way to mention you’re going back to work, especially after a break is by saying:
back to the grindstone
This is just usually plainly, and rather matter of factly, translated as:
Are there any phrases more figurative that are similar to “back to the grindstone”?
I’m not looking for any makeshift combination of words but something like 回去推磨 would be pretty fun as it calls 有钱能使鬼推磨 to mind.