You said it: one day at a time.

In depressive dips, it seems so mundane. But listen to yourself. What can you do about it? Is your mind saying you need to speak to a doctor, a therapist, a friend? Do you need a hospital stay? Do you need a "me day"? Do you need to do some service?

Sometimes emotions are telling us something.

When you cant figure it out most of the time, like me, I just try to hold on to my schedule and do a lot of "me" oriented hobbies.