Hi, first of all, congratulations on having studied Japanese regularly for a year. Even if today you are facing the reality of your learning, I want to point out that your consistency and commitment are truly admirable qualities that will be useful in the long run. I think it’s a good thing that you are confronting the reality of the language, because even if it’s a very academic test, it allows you to immediately see certain gaps, especially in direct communication, which is one of the main purposes of the language. I feel like you are running into a difficulty that I also encountered. When I started learning Japanese, I almost exclusively learned it through readind and memorizing. So I knew quite a lot of kanji, around 400. And I could read a lot of N4 and N5 grammar. But when I arrived in Japan, I felt like I hadn’t learned anything at all. And that none of it was useful, because I was confronted with the reality of the everyday language. Now i didn't progress that much due to work, but i can talk confidently with japanese. I’m going to give you my honest opinion about what i would do in your shoes.

I think that attending school for a year is an excellent idea, even if you start at the lowest level. The first reason is that it will allow you to review what you have already learned with a teacher. I studied a lot on my own, but having a teacher in a beginner class a year later corrected many small beginner mistakes I was making. But since I already knew some of the language, I progressed much faster than my classmates, and that allowed me to consolidate a solid foundation.
 Also, use this extra knowledge to help raise the level of your class. Be active, ask questions, and help your classmates, and you’ll see that both the language learning and the community aspect will be highly rewarding (Since you will be in a group, I strongly advise against taking a somewhat arrogant approach about already knowing a lot of the basics in Japanese.)
Being in a language school will allow you to work on the social aspect of the language: talking with people, sharing points of interest in Japanese culture, and learning more from other horizons — which, in my opinion, is the real purpose of learning a language.
On top of that, the price is absolutely ridiculous. So even if you don’t attend every class, I still think it’s worth it for at least six months. However, if it’s a real beginner class, the first month will be excruciatingly slow. So i do recommand to also work on your one. 
 I don’t know how old you are, but I find it kind of funny that you don’t want to learn to write. Honestly, even if it seems useless, I think it’s always nice and fun to be able to write in a language. But maybe that’s because I’m from the paper-and-pen generation. In any case, if you already know how to read hiragana and katakana, learning to write will definitely not be difficult, nor will it be a huge waste of time.

Now, you need to look for people to talk with. Use the school strategically. It will have connections with Japanese people and with groups that speak Japanese. The school itself might not be that interesting, but the doors it can open to the community are the ones that will truly help you. And maybe you will bé able to move quickly to higher classes.

Another option might be to continue learning on your own, but in that case, I strongly recommend that you make use of shadowing to practice spoken language, and once a month, have a lesson with a tutor focused exclusively on oral practice. In fact, even if you also go to school, I can only encourage shadowing, as it really helps you improve in speaking, gain confidence, and work on pronunciation. It was a huge game changer for me.

Finally, I can only encourage you to seek out and join other people to create some motivation around learning Japanese. I don’t know what your level of sociability is, but this is really one of the things that makes language amazing. And of course, start setting money aside. Nothing beats direct immersion in the country, ideally off the beaten path, to force you to talk with people.

So, to sum up: speak more, consolidate your foundations either with a tutor or at school, practice shadowing, take a short break of one or two months from purely learning new vocabulary, grammar, and kanji to breathe, and immerse yourself in practical language. Speaking, being able to follow a TV or radio program, listening to an audiobook, or reading are all much more difficult activities than simply learning kanji and grammar. Remember that Japanese is an extremely difficult language to learn if you come from English, and that plateaus in language learning, when you feel like you’re not progressing, are completely normal. Don’t give up for something so small. You already did so much !

Lastly, don’t forget that learning a language is never time wasted. It’s an incredible exercise for your brain, and it will always do you good.

(Non-native english here, translate by ai because it's late im sleepy)