What do you expect people to do if you where to tell them the truth? They can't do much but listen and try to relate, maybe they will try to make you feel guilty for revealing the way you truly feel so you would shut up about it next time they ask how you are doing. Plus mentioning these things at the workplace is unprofessional, there is work to be done and everyone has to be mentally ready to focus on work. Maybe you could reveal your true feelings when work is finished for the day and maybe they will ask you to have a coffee with them so you could talk about it in more detail...But this day and age people just want to go back home and escape from all the bullshit as fast as possible.
There's no real point in telling the truth if you have enough strength to keep that mask of sanity on until you get back home from work.
That's why i drank almost everyday to keep that mask on at work, but in the end the drinking caught up with me, co-workers began to suspect my unhealthy habit and i was thrown in the trash and replaced. I'm not saying my boss was an asshole for laying off a drunken fool, besides who would keep such people in the workplace? But i never ever told anyone my true feelings, they never knew pain i was in and they never will.