I have been teaching myself for 5 years now and I can barely hold a conversation in Polish.
Reading and writing i'm not bad with but listening and understanding is my downfall.
in most cases, it is due to not knowing Polish cases. if the constant declinations and conversions and gender differences don't start to sound natural to you, you're always going to struggle with comprehension.
the single best way to learn Polish is to hammer.....and I mean hammer the grammar. don't start going through the dictionary learning random verbs you'll never use on the regular if you can't even use basic words and conjugate them accordingly so you can have a conversation with them. "knowing" a word in Polish takes on a different meaning than most languages. who cares if you know how to say "car" or "building" or "house" in Polish....do you know how to use them in all their forms, including being able to quantify 1, 2, and 5+ of them? that's the difference.
additionally, you will forever sound
like an amateur in Polish if your grammar is not solid. accent is one thing but if every other word out of your mouth is spoken incorrectly, nobody wants to listen to you.
Polish is in a class of its own and if you want to really learn it, you're years away from being even decent at it.
Being able to turn on the TV in Poland and understand everything on a news station? A decade or more, in country + constant studying. this isn't to discourage, simply to tell it like it is. Polish is like one big monster that takes what will feel like forever to finally slay.