I, too want to study like this, since there are no Japanese teachers or textbooks anywhere near I live, and delivery isn’t safe. So yes, what I’m doing right now is watching japanese movies/shows/anime, using WaniKani, and also KanjiDamage (free version of WaniKani) and JiSho (really good kanji dictionary with readings, on/kunyomi, etc). I’ve only started a few weeks ago, and I can say that my progress has been quite good (I can already read Hiragana, at least 200 words, and some Kanji as well!)
Sadly, I can’t practice reading manga/articles or writing yet because I don’t know enough kanji/vocab. I’ve also downloaded this grammar booklet, which is apparently good, and I’m hoping to get a start on that at some point.
I don’t know your level exactly, but you seem to have some vocabulary. I think that to become comfortable using it, you need to either find a patient native, or do some “input” activities (reading/watching). This is because first you have to learn before you can use, right? Also, as you said, if you try writing then you’ll either make mistakes without knowing it or become frustrated that your sentences are too simple. I suggest that once you read/watch things, keep a small paper/digital notebook of vocab and sentences. Look over those in “spare time” that you have (eg while on public transport or waiting in line or whatever).
Don’t overdo it, that’s my main point. Often is better that cramming, as I’ve learned while learning other languages.
Then, once you know more, you can start writing, and maybe even getting someone to look over your work (that amiable Japanese-speaking fellow, maybe?).