Seiyuu: after high school

Hello there, I'm 15 and a half-japanese living in Brunei. I'd like to ask a question on what to do after high school to pursue voice acting(and singing). Next year is my last year of education(upper six).

My japanese is pretty ok. I passed JLPT N4 and am about to self-study for N2/3 next year.

I've been in the drama club for 4 years now in my school and I have performed as a main character in a competition once. So I could say I'm fine with acting(but I am better at script reading and relying on my voice than conveying emotions through body language sometimes). I am planning to join a local drama group next year.

My grandparents live in Tokyo, and once I turn 18, I will change my nationality to Japanese(half-japanese people can do that.)

I checked and there's a voice acting school in Tokyo: The Tokyo School of Anime, which I think is a good school(caters to both acting and singing). I am planning to go there once I get the chance, but the fees are hella expensive.

Should I go to a production company and take lessons there or should I go to the school?

..

And if so, which production company? And details of lesson fees and stuff?

My singing is alright, I guess. I love to sing haha. I posted a cover in my niconico account... shinamizuri(my username).

Please help. Thanks

I'm not sure if anyone here is a seiyuu, but I heard that becoming a seiyuu is extremely difficult. There are so many people who want to get into voice acting, but obviously there aren't too many jobs for it.

But if you're really up for the challenge, go for it! Sorry that I can't really give you any useful tips, but thought I'd chime in since no one else has.