optimusamicustaphobia
Fear of being in love with your best friend...It might hurt your relationship with the person, especially if your best friend is the same gender and their orientation isn’t homosexual. And if you openly say you like the same gender, they might stay away from you and you end up lonely, leading to phobias such as claustrophobia or mono-phobia.
Leah suffers from optimusamicustaphobia, therefore, she cannot tell her best friend how she truly feels.