I have been raised and spent the majority of my life in Western countries (でも今日本で住んでいる) and while I definitely think there is a lot more understanding about mental health compared to Asia, many people still believe that someone is being difficult on purpose if they have any mental health issues. Especially if someone has a chronic condition and isn't able to get better, they're treated like a selfish, lazy good for nothing rather than a person struggling with a genuine life-altering malady.
I was raised in a traditional, very conservative environment, so I had to hear this type of rhetoric all the time. My grandparents were poor farmers, and eventually got into factory work as a ticket out of poverty. So all the time growing up, I had to hear about how my generation doesn't know what real suffering is and we are so sensitive, because in previous eras no one can afford proper clothes and shoes, or they got beat harder by their parents for not working hard enough, so surely I should be grateful that I was *only* beaten with belts or sticks rather than kicked or punched. To most people where I grew up, having any sort of mental pain is a deep weakness, that you fully can control by "choosing not to be a victim". Some people will even point out how it's an embarrassment to your family to openly have any sort of mental illness, which is beyond cruel.
One of the most common guilt tripping platitudes you will hear as a suicidal person, imo is "think of how others would feel, would you willingly break your loved ones hearts out of selfishness? You have to live for them!" and trying to impart that collectivist sense of obligation onto someone, regardless of how others are actually treating you. So I think that while people are certainly more open to talking about this topic, understanding is very rare to find, from my experience.
In the UK especially, I was shocked by the level of callous behaviour I saw towards people with mental health struggles, despite the UK being a country which openly advertises itself as progressive and collectivist in a manner that protects society's most weak and vulnerable. I remember the first time I was on a train that was delayed due to a suicide at a nearby station, and I heard multiple people grumbling, complaining, and even insulting the person. The sheer lack of compassion was crazy to me, especially when you see posters everywhere in UK train stations with mental health PSAs and encouragements to reach out for help. It feels like such a facade.
Also, in many Western countries now, mental health services and provisions heavily push accelerated CBT sessions and SSRIs and nauseum, with very few options for people who do have severe issues that aren't solved by the most basic and cheap treatments. Actually, the only medication that has ever helped me during PTSD episodes is pretty much being phased out in a lot of Europe and Americas. In Japan, I can easily be prescribed this class of medication, but in most Western countries, they would rather people have absolutely nothing than take a potentially addictive medication sparingly, as needed. Though I was warned by my psychiatrist's assistant that I shouldn't allow any of my Japanese acquaintances to know I was going to a psychiatry clinic or they will think I am a difficult person.
Despite this, I do think many people in Japan believe that with just a pill, you can be always be fixed and 我慢 endlessly, just like Westerners do with psychological therapies. It is a really toxic mindset, especially if you can't keep up your たてまえ, the constant pressure to be genki and energetic is so corrosive when you're already feeling terrible.
During my time living here so far, I witnessed a man sitting in a position which was causing him a lot of pain, but the people around him refused to let him sit normally at the table during the meeting, because ルールはルールだ, which I think highlights a major issue in Japanese society of making individuals suffer just to keep up a pristine or professional image, which in many cases is completely unnecessary and just making things harder on everyone. So I really do feel for you, because even as an outsider, I have seen how harsh Japanese society can be to anyone who is suffering.
I live in the philippines, I think people here don't really care about mental health much. For me, it feels like people who have mental struggles are treated as lazy, not trying hard enough, and incapable/unskilled
I think we have something a little similar to "gaman," but it's more family focused. We have a value called "utang na loob" or debt of gratitude, which is to be grateful for what you have received, and to give back/repay the grace you've been given. This applies the most to your family who has raised you and have taken care of you all this time. Many would be pressured to follow what their family wants/needs even if it's against their wishes for this debt of gratitude. There's also the breadwinner culture which is having the most successful or capable member of the family to provide for everyone, and filipino families are large. For financially-struggling families, the breadwinner or provider has to give up everything oftentimes.
Basically, family is more important than yourself. If you don't put them first, if you don't repay them, you're selfish and ungrateful. It doesn't matter if you're struggling too, because it's your role to live for them...
Ofc this isn't true all the time, and maybe I'm having too much of a doomerist view on this, but it's just how it feels for me
Also regarding suicide, people do talk about it as a tragic thing, but with a controversial undertone? Like "Oh hey did you know that [X]/ did you hear about [X] committing suicide?" It's like a topic for gossip
There was a case a few months back wherein this student jumped from a train station bridge and fell on a car. Some people's reaction online was "You're dying, but also inconveniencing others?" But there was also some who seemed emphatic and didn't blame the student at least...I think people were pissed or mad at the student because the police handled the case quite stupidly. "We're trying to find out if the victim died from the fall or from the vehicle," and if the car hitting him is what killed him, then the driver would be arrested which is unfair...Not sure what the ending was for this case, never looked it up again
One of the people closest to me is also Filipino and suffers from several mental illnesses and I've experienced everything you've wrote here firsthand with their family, so I don't think you're doomering at all. Unfortunately it seems to be common especially with families who care a lot about status or success, they will actively shun and publically complain about the sick relative. Even though they know aking mahal is suffering greatly, no one has ever turned a hand to try and help or understand them.
It's even more infuriating because like me, they have also been abused by some of their family members, to some degree even worse than I have especially in terms of physical abuse. But the entire family both in ph and diaspora pretends like it never happened, and that everyone needs to pretend like everything is fine, and that family comes before everything else, even when family is actively making someone's life a living hell.
When I went to ph before, some of these family members took me aside and asked why I wanted to associate with my friend (at this point we have known each other for years and they have always been dear to me before we got even closer) because they're an embarrassment and not successful, despite the fact that no one has ever tried to help them with the mental illnesses they've been suffering with for years. I was completely floored and infuriated these people who claim they are full of love can say such things, but I think it boils down to that attitude of seeing struggling as selfishness.