Two things to work on:
First, pay attention to circular thinking, especially the way I pointlessly rethink and overthink things. The tendency to wrap myself in loops seems to be at the heart of a lot of mental crap, and I believe is directly related to the depression. She specifically recommends enforcing some mental downtime on myself: that is novel and scary enough an idea that it is probably correct. Pharmaceutical options exist if I decide this is a Serious Problem, but I want to try working this through first.
Second, keep working on the Opportunity Cost problem. This underlies many bad habits, possibly (indirectly) including the inability to let my brain shut down. I seem to be making some progress on this front; keep at it.