I do pretty much what you do.

I didn't make decisions, don't project the bad feelings into the future and don't fully myself into doing the things that interest me.

Basically, I "hold still" and wait for it to pass. Sometimes it takes a few hours,a few days, or it can stretch into weeks like it happening to me now.

If I absolutely have to do something, I'm break it apart into much smaller and more manageable pieces.