The only way I made progress in latin was when I bought a few books and started reading, beginning from (modern) children fairy tales. This actually gave me a lasting knowledge which up to this date allows me to read a simple latin text or guess a meaning of a word in English or French (neither language is native to me).
Speaking latin of course takes it way further but I think the direction is the same: learn it as a living language not as as a dead one. Starting from declensions and cases gets you nowhere, judging from my friends who learned it in school for years with zero results. Instead, start using the language, if only for reading. Then you can return to grammar later if you ever want to become proficient.
I also recommend this guy [1] who not only shares the same approach but apparently have fully dedicated himself to it. He has books, ebooks, audiobooks, a mobile app and a youtube podcast, all in latin. I can't cease to be impressed by the effort and the quality of the content. In comparison the Duolingo latin course is a complete disappointment.
I started with LLPSI along with Oerberg's companion books (Colloquia Personarum, Fabellae Latinae, Fabulae Syrae). After that I read Hyginus' Fabulae and then Commentarii de Bello Gallico by Caesar. Since then I've read more Caesar, Nepos, Apuleius, Seneca, some Livy, some Catullus, some Cicero, and I'm currently reading Ovid. I did this by reading Latin for at least 1 hour every day since the first COVID lockdown in 2020, even if I was sick or not feeling it I made sure to get my Latin reading in. I did do a lot of grammar drills in the beginning, and I made an Anki deck for vocab. Grammar drills definitely help big time, along with jumping in head first with a book like LLPSI and reading from the get go is the way to go IMO.
Did you ever read Roma Aeterna? Or did you go straight into literature?
I just looked at my backlog book and apparently I did read the first half of LLPSI 2. I don't recall much from it though. I think after a certain point in the book, I found it too difficult straight after LLPSI 1, which is why.
I went straight into Hyginus and Caesar. Hyginus is not difficult at all. After LLPSI, you should be able to read this: https://www.thelatinlibrary.com/hyginus/hyginus5.shtml
Caesar is not too difficult either. The biggest problem I had with Caesar was that he used indirect speech a lot and LLPSI doesn't really prepare you too well for that, but you get used to it.
Very good yes. Such is my experience, not only with Latin. Received language instruction may have it exactly backwards.