Therapy and medicine won't help. Usually the answers are: clean up the negative people around you (fire that person as your boss, network and take tons of other interviews sufficient to move or have a fallback option so you worry less), and branch out on your actual life (travel more, do something new, etc.)

You could also accept that Faangs are full of slackers and coasters--stop tying your self-esteem to your work or your boss (who is actually your adversary, squeezing as much work from you for the lowest price). Do enough to be of interest to other teams there, have a few references and savings and just assume you will be let go, and focus on improving your life and your next opportunity.