For those of you who are good at learning languages (preferably many languages at one time!) do you have any advice for me?

I am a native English speaker but am currently learning Swedish and French. I have devised a system whereby I read one book in English, one in Swedish then one in French and so on. While I am reading my Swedish book, throughout the day I will only think/talk in Swedish (to myself of course) and so on. Which means, I have 1-2 weeks where I am only focused on one language. I am wondering if perhaps it may be better to instead of separating each language by weeks, have a system where one day ill have one language, followed by another language the next day and so fourth ?(I am seriously trying to become fluent as quick as possible)

Any other tips on how to learn a language as quick as possible would be great!

(I also do the other things like duolingo every day, watching movies/tv shows/radio in each language and so on)