I've noticed my "cycles" begin with emotional event / stress, e.g., a particularly difficult therapist session or a stressful family visit. It rarely starts with that actual event, but rather it's like a pressure cooker starting, then I start becoming more jumpy / irritable. Then a few days later or a week later, I shut down.
I'd track your overall sensitivity to normal stimuli as well.
I'd track your overall sensitivity to normal stimuli as well.