Thorns and roses

Giyuu does not return your loving feelings you know this because you had Hanahaki disease which caused the one diagnosed with it to cough up flowers the only way to cure the disease is either you have the flowers growing in your body removed also not remembering the one you loved dearly or the person diagnosed they love would truly return those feelings otherwise the flowers would become roses if they weren't already and the one diagnosed would die an extremely painful death hence the flowers were to completely destroy your organs from the inside. Enjoy!