Be kind to yourself and accept your feelings and they will pass over you.
You see other people at their best, every body has down times, dont compare our private feelings to others public face.
Do fun things if you can !
Give to others.
In the nearly 30 years I've faced depression, I've found three essential tools when I'm so sad that I can hardly find the energy to imagine ever feeling better. They may sound simplistic, but simple is what I need when I'm really down.
1. I try to keep in mind every hour or so, sometimes writing it down for myself, that there was in fact a time when I wasn't depressed, so this time, too, I can expect it will lift
2. I talk to someone, especially a trusted therapist because they make no judgments, and find it helps just talking through and describing where I'm at
3. I clean, I garden, I scrub the floor. Somehow I find enough energy to clean something like a counter or sink or pull some weeds. I can ground myself physically and mentally with thoughtless work, which tends to continue for 30 or 60 minutes, distracting me into some simple meditative place.