Strategies for when the pendulum is about to swing to depression?

Summary After years of tracking, I've identified a pattern and trigger for depressive episodes happening within a one week range.

With such a clockwork-like pattern and well recognized warning signs, what can I do to help against this?

(If it's relevant; I use lamoTRIgine & Topiramate and regularly attend therapy)

Detailed

I'm very fastidious about tracking and recording all manner of things in my life, whether related to my BP or not.

I try to go to the gym regularly (ideally I'd like to go 3-4 weekly but my average is more like 2.5-3) but it has nothing to do with trying to manage symptoms.

I've recorded everyday I've gone to the gym (plus the day of the week) for the past ~3.5y and, in all but maybe one or two instances, whenever I'm able to go 14d+ in a month, the following month, within the first few days, I begin an intense depression, enter a binge eating episode (as in gaining 20lbs+), and totally lose motivation to workout.

It begins with me being too tired to go to the gym one day that I planned on going (no biggie, who cares, the world won't end if I don't go workout once).

Then I skip again, then after dinner one night I'm still a lil' hungry so I have seconds or a snack (again, no biggie).

But then I go back for a lil' more, then more, then I've stayed up all night eating a whole box of ice cream sandwiches and pizza, and the next day I'm unmotivated to do anything, it all starts snowballing, and it's like I take a month long hiatus from life.

With such a clockwork-like pattern and well recognized warning signs, what can I do to help against this?