Before you start any therapy you should try to understand yourself, by tracking yourself, as in the quantified self. You work at a FAANG so you could probably develop your own tools to do this. Track your mood, your sleep habits, exercise, activity, meals, caffeine intake, work productivity, social interactions, medications, etc. Then look and find insights into how these relate to your work attitude. This project might in itself give you motivation and who knows, maybe you can develop your own startup to build this as a product