Thanks for commenting @PeterthePapercomPoser!
I did not know the prelude by Chopin. I think it is famous as somehow I think I heard it before, but I was not aware of its existence (really nice prelude, though!). The model was a really really simple Czerny beginner piano piece, a waltz, really simple. I used it as a model for the harmony and chords inversions of the first section, and that is the end of the commonalities. I guess my mistake was using as model for a slow piece a fast piece, since slow pieces need to be treated much different to a fast one.
After composing it a similar piece came to my mind: Bach Adagio for Piano BW974. It is actually a Alessandro Marcello that Bach transcribed for the piano. Incredibly beautiful. The whole piece, with the exception of the coda and a single bar, has a constant accompaniment. However, there the accompaniment is less heavy since most chords are quite high (on the contrary to my piece or Chopin's prelude).
For now, I deleted the repetition of the A section after B section since I felt that was the weakest part of the piece and also created a new Coda for relaxing the ear after such a constant stream of chordal accompaniment. I also tried to fix volume issues (with this accompaniment, making the volume correct between melody and accompaniment is so important) and modified the B part so it gets less "bass heavy" at times. No substantial change but I am happy it improved a little bit at least.
Thank you so much for listening and commenting!!