Hi look I can't speak for Polish directly but as a polyglot I can tell you that it is a matter of speaking and listening a lot. Also try to have real conversations with people with your voice. Your brain isn't used to recognizing the words of the language because it's a completely new overwhelming amount of information. It's a matter of getting used to the speech and over time you will understand more and more. It's like running. If you never run, you will never be able to run for 10km. And even if you start, you'll need some time before you can run 10km effortlessly