Yeah, it's a lot of work and it's been a long journey already. But I'm at least past the point of feeling like I'm a failure for not finishing it sooner, which held me back quite a bit. Now I'm letting it take the time it needs!
What I've been writing is basically a coherent set of chapters full of bullet points with text around them. Some things go way too fast, but I know that the rewrite will more or less double the contents, so I'm not worried about that. It's sometimes better to not fret about the descriptions and flowery text and just get something down on paper. That way things get done!
And yea, the early silliness (it was extremely silly) will get smoothed out a lot. I introduced a new character about half way in from where I am now, and she's more down to earth and actually has a character, as opposed to the others, who are all just tropes in a bag with a bow on top. I've tried giving them more motivations as I got serious with it though.