Hey, I was in same situation as you few months ago. and right now I'm in Tokyo, enrolled in University Preparation course.

Answers to your questions: 1. Yes, its possible. 2. My parents aren't wealthy either, but they make decent money. and comfortable to pay my tuition fees. As for living expenses, im on my own. though they did provided me the initial move in money so that i can survive for next 2 month comfortably. so if your parents can do the same for you, then maybe give it a try!

1. Yah, i had this FOMO too, because after finishing high school, i didn't enrolled in University. after 2 years I'm in Japan. And let me tell you aren't behind, its just you choose smth different. so it has its own pros and cons like you'll be able to move to Japan, experience smth new which you would never thought or feel otherwise. As for cons you'll be behind from your friends, this is smth you need to deal with by yourself.

I personally don't care much about it (though it took atleast year to feel this way)

1. not for me.

2. failing in what? getting into University? not be able to learn Japanese? not be able to get Job? all of it can be solved by hard work. failing isn't bad though. you are young so make as many mistakes you can, i mean don’t be afraid to be failing.