Fake it til you make it got me to a tremendously depressed state (suicidal) without being able to talk about what got me there. It took a lot of therapy to feel OK about opening up. I still feel like I can't let people see how much pain I'm in every day. I just smile and move along as I can. Maybe one day I'll feel OK about that, too.
There is so much in depression deeply felt that is impossible to share. People in general don't get it. Lucky them.