Emotional stress can be so exhausting; so much so that often it can totally take the air out of your tires for days at a time. Instead of dragging down your whole week, stop and try to put in a tiny bit of effort in to flip the script on your mood. It can be pretty easy if you go into it with an open mind and get ready to absorb a new attitude. Soak up the smiles, and try to play around with one or many of these ideas to change that mood.
There is something to be said about getting outdoors, soaking up the sunshine, and breathing some fresh air. The mind loves to be in nature feeling free and it will at least get you out of the office during the mid-afternoon energy slump. If it's sunny out at the time, even better this will truly spike your mood in the right direction.