Businesses come and go and they are not more important than your life. And money is not more important than your life.
First, you should congratulate yourself on taking such an impressive personal risk by moving to a vibrant, different place -- you sound like a very interesting person. Be glad that you are experimenting in life because that's all we really get during our time here -- a chance to try new things. Many people never find the courage to do that, and those who do quickly learn what you have learned, that experiences are unpredictable when you stray from the norm. This is a good thing and it means you are putting yourself out there in the universe to see what is on offer. Now it's time to deal with the next step.
I feel your pain. I know exactly what it is like to feel backed into a corner when the short-term view is a combination of stressful and terrifying.
But it's only the short-term view. When I look back on those moments in my own past, the details are long forgotten, the misery is remembered and I remain glad it is in the past.
Wise man once said: This too, shall pass. And it will. I promise you that. Get through the darkness, there is light on the other side -- guaranteed.
What you need to do is minimize the stress in your life and take responsibilities off your plate -- starting with the business, the work, the overall lifestyle, all of it needs to be reduced or minimized or removed entirely for awhile.
Put yourself in a position where you can do nearly nothing for awhile, except reflect, get some positive interactions with whoever you are close to in your life, whether it is friends or family (or no one, if you are truly comfortable being alone), and don't ask anything of yourself except to take a life pause with no other demands.
During that downtime, give yourself permission to do nothing, to explore your creativity and interests with no pressure to make anything come from them. In the absence of pressure, life has a way of illuminating the real goals.
Japan is always going to be there. You will enjoy it more and perhaps even prosper well if you first learn to relax and enjoy life again without so much pressure.
It's fine if you end up losing a little money to close the business, and maybe even leave Japan for awhile. It can be very stressful to live abroad, and Japan is arguably one of the most challenging because of how different the culture is (assuming you are coming from somewhere in the West).
I have lived all over the world and done so without much money, and it has not always been easy. Feel free to contact me if you need someone to talk to.