If there's a chance, try getting an opportunity to study and work in Japan. That's definitely the fastest way to master the language huhu. In fact, when we barely use the language, our fluency goes down T___T

Need to save up though
I feel your pain. I'm definitely worse off, getting confused over my sentence pattern and how to modify them. When to use what etc. Short sentences are fine but tend to struggle with longer sentences. Really need to make time and be more consistent in studying and revisions.
It was even painful trying to read that (to no success lest google translate is used haha).
How has it been working in Tokyo?
JLPT exam is held in July and December each year. The rest of the info i suggest you Google and run through the official site.
Taking up the exam is not as simple as just being able to read; it's also about being able to understand phrases, grammar, comprehensions, listening etc.

Yes self-learning is very difficult. Other than good discipline, it also takes longer time trying to understand the basics and learning the grammar, particles etc.

First thing you'll need to do is stop writing or reading in romaji. It should be fully in Japanese and try to avoid writing the furigana on top of the kanji if possible. Try to remember the Kanji and practice writing through various free apps.

Lastly, you may want to consider enrolling in an institution to help get you started on the basics. It's a great deal of help learning through a teacher.
Hahahaha yes indeed, that's always the case. But don't give up, there'll always be such opportunity! Broaden your connection and network.
Good to hear you're doing well! It's not easy but 頑張って！