Gareth Fernandez returns with the spiritual successor to his 2019 hit, “Achilles,” and 2020’s heart-wrenching ballad, “Put You Through.” His latest single “Could Have Been Us” is a soulful ballad that soars with sublime arrangements and emotionally resonant songwriting. The inimitable indie darling Linying (Sticky Leaves, Paris 12) co-wrote the song with Fernandez, and also lends her hauntingly beautiful vocals…