Idk if it is exclusive to the corporate sphere of work in Japan but there is a crazy notion that anyone who takes more than two consecutive days off be it sick leave or annual leave is "lazy", there also seems to be a huge deficit in terms of mental health care based on the tidbits I've read.Go see a therapist imo. The problem is persist and detrimental enough that it cannot be ignored. Going to see a therapist is probably frowned upon in Japanese culture. Most of them are expected to just tough it though.