Good mix, it's tasteful. It however feels near totally peaceful and uplifting to me though, contrary to your stated intention. B-flat major shifting into B-flat minor is hard to catch, and it still makes a form of the plagal cadence with all of its associated euphoria when moving back to F. Discernible moody undertones would have to come from more elaborate diversification in harmony and/or sound selection and filtering.

thx.

Beautiful! I love how it opens up in the middle, just a huge rush of emotions

Really deep, just... amazing, awesome work.