Congratulations on your creating a song with a chord progression with which you are happy... From you writing it sounds as though you like you song structure but are not sure about the overall sound.
1) if you are happy with you melody, experiment with altering the octaves. Maybe he melody line can be played in Octave 3 .Perhaps the octave 1 is too low and "muddy". On a piano octave 1 is extremely low.
2) Have you tried changing the key? Perhaps you will find a key which works better for you.
Hope this helps.
Andy