I've been learning Spanish using a method called "Comprehensible Input" in which basically you just.... watch and listen to things in Spanish. That's it. No translation. No grammar study, no vocab memorisation. I've been at it about 9 months, and almost 800 hours of listening/watching time. (Which is about half of what supposedly will get you to conversational fluency, at least for romance languages. Less related to English languages can take longer)

It works. I can understand day to day conversation easily. I'm watching Breaking Bad with a Spanish dub. I can read YA novels (and listen to audiobooks). I miss some words and phrases here and there of course, but I still get the meaning from context most time and that helps me learn.

My speaking lags significantly behind my comprehension skills of course, as I've only practiced that a small fraction of the time. But it's grown leaps and bounds. I can speak 10x better than I could a month ago. Supposedly it doesn't take nearly as long to develop that skill once you start racking up listening/reading hours and that's been my experience.

The beginning is a slog though since you have to watch things you can understand.... Which basically amounts to videos of people talking at you like a baby with drawings and hand gestures so obvious that you can understand what they're saying even if you muted the audio, but once you get to the point that you can understand actually interesting content it becomes SUPER easy. You just replace all the time you spend watching and listening and reading things with.... Watching and listening and reading things in the language you want to learn. Once you reach that point it doesn't take effort. Learning Spanish has changed from something I'm trying to do to an inevitability. It's honestly like magic. If I've gotten this far in less than a year I can't imagine where I'll be in two.

If you're interested in the method check this playlist and this guy can explain in detail (turn on English subtitles if you don't understand Spanish): https://youtube.com/playlist?list=PLlpPf-YgbU7GrtxQ9yde-J2tfxJDvReNf

I'm not trying to advertise for the site he runs, you can totally apply the method through free resources (and he has hundreds of free videos for this too). But it is an incredible resource that's super cheap and can get you past the beginning stages. I've moved past their content at this point but it was invaluable in the beginning.