Duolingo chaos: many years and languages, little progress

I started doing Duolingo (almost) daily 1426 days ago, that is almost 4 years.  I started with Mandarin Chinese. For almost 2 years I was doing Chinese only every single day on Duolingo (I studied it before! At university and with private teachers!). Eventually I had finished the Duolingo Chinese course and moved on to other languages. I couldn't decide which language to pick up next, so I started with Russian, then French, then German and started bouncing between languages often without commiting to a single one.  >Which of those languages do you speak? The result is that I do not speak any of those languages well, except for French because it is very similar to my native language, (Brazilian) Portuguese, but even then it is not good enough. On the plus side Duolingo updated their Mandarin Chinese course, so I can get back to studying and improving my Chinese, but honestly I am a bit unmotivated. I have been studying Chinese for, I swear to you, over 10 years, and I am still stuck at HSK 3. I am nowadays interested in germanic languages such as German, Dutch and Swedish, but I can't pick one and dump the others, which HINDERS PROGRESS and slows me down. If I don't pick a single one and commit the next 2 years will show as little progress as the past 2 years. My other languages will not get as good as my Chinese and my Chinese also will never become fluent. I think I have linguistic commitment issues.