I lean into it when it shows up by listening to extremely depressing music. I put my headphones on, lie on my bed and just listen or sometimes cry. Then I go on with my day.

What's been helpful to me was when someone told me emotions are like the weather and they pass through us and sometimes certain emotional "weather" prevents us from doing certain things. So, today may be "generally happy with a grief cloud passing through from 2-4 PM, followed by gradual clearing" or "a sad day with some happiness breaking through periodically throughout the day."