My 1200 day streak was actually first Portuguese, then Russian (with some overlap), and I've used many other resources to help learning in both cases, I never only did Duolingo for long amounts of time. I don't think using only any single app or method is a good idea anyway, they all have their pros and cons, things they're good at and things they're bad at.
My Portuguese is good enough to have day-to-day conversations and I can read things like newspaper article without problem. Note that my native language is French though, another Romance language, so the gap was really not that large to begin with. I'm sure you must find the complicated French conjugation system, plus the gendered nouns a bit of a headache if you're a native English speaker. That stuff works pretty similarly between French and Portuguese, so I had a big headstart here, I could just focus on memorizing the differences (the portuguese subjunctives can go fodar themselves by the way).
Russian is a whole other ordeal however, I still have a long way to go until I reach fluency. I can usually decipher newspaper articles okay-ish, but oral comprehension is still very low and my ability to construct the language is still pretty basic, although I could probably go through a simple conversation with a native with a lot of effort and many mistakes. The main difficulty at this point is learning and remembering all that vocabulary, I can't rely on cognates like for Portuguese and to a lesser extent English. I need to relearn basically everything. That takes a lot of time, and Duolingo really only gets you so far.
I'm so jealous that you learned French as a native. The language is such a pain. I had some basic education in Spanish and Italian before starting French, so I was familiar with the concepts. (In fact, I'd been starting Portuguese on Duolingo in preparation for a trip there, but with all travel being put on hold I switched back to French.)
English is a big leg up on French. Some of the cognates may be unfamiliar or dated, but I've got a big English vocabulary and a lot of that has French and/or Latin origin. I'm still very bad at advanced conjugation, in part because things like the subjunctive and conditional just don't come up in as great a number (as well as being more complicated than their English equivalents).
I think all of us who yearn to master a foreign language felt that way at some point. When some concepts seem to fly above your head, you gain new appreciation for the natives who can just juggle with all of that intuitively.
One thing to always keep in mind is that there's no trick really, learning languages is not about being smart or being super good at anything, just having enough discipline and dedication to keep working at it until it starts making sense.
Thank you for your kind words and bonne chance à toi aussi !
My Portuguese is good enough to have day-to-day conversations and I can read things like newspaper article without problem. Note that my native language is French though, another Romance language, so the gap was really not that large to begin with. I'm sure you must find the complicated French conjugation system, plus the gendered nouns a bit of a headache if you're a native English speaker. That stuff works pretty similarly between French and Portuguese, so I had a big headstart here, I could just focus on memorizing the differences (the portuguese subjunctives can go fodar themselves by the way).
Russian is a whole other ordeal however, I still have a long way to go until I reach fluency. I can usually decipher newspaper articles okay-ish, but oral comprehension is still very low and my ability to construct the language is still pretty basic, although I could probably go through a simple conversation with a native with a lot of effort and many mistakes. The main difficulty at this point is learning and remembering all that vocabulary, I can't rely on cognates like for Portuguese and to a lesser extent English. I need to relearn basically everything. That takes a lot of time, and Duolingo really only gets you so far.