I think the important thing is if the song (or book, film...) was made for your countrymen or for foreigners.
I had not thought of it that way, but yes. That makes sense. Now you have me curious and I will probably look up those other songs. However, I'll never know what it is they said. I only know a few words in Polish.
As for your English....it is very good. Any little imperfection adds charm. I love accents. And I especially love Polish accents. How cool that you want to share your country and life with English-speaking people and have made a song in our language. And it is nice for us to hear that you are Polish, not English, not American. :-D
I sent the video to many of my friends and everyone was very positive. In fact, a sociology professor with a PhD from Alabama who is also a musician enjoyed the slide guitar. He has also expressed the thought that maybe he will visit Poland one day. See? It has had a good effect.