If it gets too bad, can you keep a notepad in front of you where you can write what you really want to say to people? Go all out until you get so over-the-top with it that even you have to smile.

And breathe. Sometimes I just play the phrase "all I have to do right now is breathe in and then breathe out" over and over again in the back of my head. Thinking about holding it together for longer than each breath, much less until the end of the day can be overwhelming sometimes, so breaking it down breath by breath until the very worst "I want to dissolve into the floor" moments pass can be helpful.

Hang in there! You've made it this long and that counts for so much! Give yourself lots and lots of credit for that.