My own experiences learning French, German, and Russian have been quite similar. Apps are fine to help with certain things like pronunciation, but they can’t teach you a language and they can’t help you seriously master it.
I found that for me besides constantly having conversations in my head, reading lots of books and watching lots of films in my target language made all the difference.
The way people actually use language often can’t be boiled down to sets of rules that can be memorized. Unless the rules become so arbitrary and numerous that they become impossible to learn.
Novels and films make it fun to internalize how languages actually work and how people actually talk. Which makes those internal conversations more helpful.
And those meetup groups way less intimidating.