I have some suggestions about why your song got "bad":
Firstly, is too noticeable that you used stock instruments. Try experimenting with synthesizers. If the tool you're using don't have synths, try adding smaller effects to your sounds and layering more sounds.
Also, the mastering isn't that high quality, so maybe watch a few tutorials to help you with that.
It would also be helpful if you tried to stick with a genre or feel to your song, so that it would be easier to understand your idea with the song.
And last, don't give up, because it takes time to make good music. And I'm saying that as a music creator myself soooo