Sorry, but this is nothing but empty stereotypes and borderline racism. Yes, corporate Japan has work culture issues, but at the end of the day Japan is built on the backs of small businesses, which, despite struggling with the times, typically offer a lot more job stability than a lot of western corporate jobs. To say everyone is sexist and racist is a wholly inappropriate overgeneralization, and the war crime thing is hardly a thing in the public consciousness at all. Yes, the ultranationalists sometimes get a lot of press, but they're basically schoolchildren compared to the western alt-right these days. There's plenty of activisim and progressivism going on, and while the wheels of change turn slowly here people are trying. Social support programs are lightyears ahead, there's no toxic culture war, and people are generally much more respectful towards each other. In my experience foreigners tend to form bubbles not because the culture is impenetrable (it's not) but because they aren't willing or able to put in the effort to overcome the linguistic and cultural barriers.

Also, OP, don't make up pissbaby excuses for yourself. I was diagnosed with severe ADHD back in first or second grade and have been living in Japan for nearly 10 years. I'm not saying it will necessarily be easy for you. However, you're not going to die without meds, and there are plenty of nonpharmaceutical strategies to help wrangle the ups and downs. Personally, I found there to be significant mental health and self esteem/identity benefits to reducing dependence on medication. At the end of the day, remember that some Japanese people struggle with ADHD too!