A best friend who found a boyfriend

A famous movie dialogue says in relationship and friendship, relationship wins. And today I feel that line really true. When you are really close to someone and that someone when leaves you just for the sake of relationship, it hurts. Because once upon a time you used to be the one with whom she used to share secrets. But now you are no one to her and her bf is everything. Beacuse of all this relationship shit many best friendships break. Then the best friend who used to take care is replaced by a boyfriend. I grew into love with my best friend. Our friendship could've been turned into a relationship but that friend lied saying that she wants to marry by her parents choice. Then that same person comes and tells me that her another closest best friend is her bf and starts to share his and her moments with me. The amount of hurt I felt was tremendous. I decided to end that friendship. But unfortunately I still can't end that friendship thinking of how it would hurt her. Idk she cares for me or no but I cared for her and that's my truth. Now also we talk to each other but it's just like a formality, like for assignment or for works but that bond is somewhere lost. Idk where to find that bond. But the dialogue in relationship and friendship, relationship wins was proved true to me by her. It still hurts to me but I can do nothing but just feel my pain to myself. !!!!! If you wanna choose relationship only at the end then don't choose friendship ever. You may not know how much it hurts to the one who cares for you.