Hi Josie,
I completely understand what you are saying! I am able to function during depression as well. I feel really really bad, but I drag myself out and do the bare minimum of what I need to do. I don't think other people would even know that I was depressed and not doing well! I am just now learning to recognize the depression and take care of myself during this time. Hang in there and speak with your doc if it continues.
~Daisy