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Unfortunately, having an education in Asian communities and having proof of it is paramount. And it proves that you as an person can sit down and commit to an profession - as well as learn from others and from your own mistakes. With out that piece of paper saying that you went through schooling, you will have to work from the ground up and most likely on your own unless your talent is phenomenal and/or unique.

In your case, I see it a bit difficult given that those aren't the principal fields that Japan is looking for.
Being principally these:

0) Engineering
1) translation,
2) IT,
3) modeling,
4) gastronomy
5) and entertainment ( not manga, not anime...This is considered a taboo and only those that have an art's degree can presume of being mangakas)

As American, you can enter inside English Teaching, but for this, you need to have your university degree (bachelor or master)
Also to travel over there, you need to prove that you have financial back up. (2K approx.)

Do advise to consult official pages about the matter, given that there are several working visas and which I'm talking about are the more common.

I do comprehend your point of view, what you study inside educational institutions, is not what real life is, but still it does help you somehow and if you have to run under that "tedious" process, you simply have to do it, with a lot of patience, because "those that wait, receive great rewards".

Now-a-days, a diploma won't open entirely a door, but at least will give you opportunities.

We are not looking down at you, we're just putting things just as they are. Japan is a very different society, they do encourage studies (Their learning do not end in high school or university, there are people of 75-80 years old and they still going to school to learn something else) and improvement. You rarely will see people that do not have a diploma from university, in fact with the actual economic life style, they do fight to get inside the university, otherwise would be kinda impossible to live in a so expensive society...what you watch in anime/manga is a true daily life story. ( school life gender)

*ehem*

A degree is rightfully yours when you make an enforcement to get it. (homework, day/night/dawn studies, presentations, money investment, good scores, etc...)

So, do advise you to retake your studies, do not give up in trying your best. Probably you didn't like what you were studying, there is always the option to search for something that you like or would like to do as a profession also if you aren't sure, you can take a test of your abilities. But you have to look of what is convenient now-a-days and future too.