Most people just severely underestimate the amount of work it is. You probably need 1,000 hours of listening to be decent, and 2,000 to be strong. If you practice 30 minutes a day, that will take 11 years.
So the only “trick” is that you need to find things that you genuinely enjoy doing in French. So that you can practice for multiple hours each day without burning out.
I’m a native English speaker who has a very high level in Spanish. It takes a long time for your brain to figure out how to decode the type of mumbling people use in casual speech.
Yes, practice vocabulary, practice grammar, read. But you’re probably already doing this. You just need to listen to a ton of stuff right at the edge of your abilities and you’ll notice improvements every few months.
My one final tip would be to not get in your head so much. Literally everyone who has learned a language will tell you that if you review vocab, do grammar exercises, and listen to the language for 1-3 hours every day, you’ll learn it.
But it happens so slowly that it doesn’t feel like it will work while you’re on the journey. It’s sort of like the gym: if you lift every day and eat healthy, you will have muscles in a year or two. But it’s really demotivating because you won’t notice a drastic difference even after 3 months.