Reverie is a state of relaxation where the mind floats freely and ideas from the Unconscious,from the imagination can enter the mind .
Reverie is not self centred.
Fantasy is daydreaming in a n ego centric way.Imagining you are doing wonderful things,attaining success,love etc.If we over indulge in fantasy,that can be a problem.The gap between desire and actuality is hard enough.Fantasy makes it wider.. that is my personal view.
How my heart sings 