My friend (20M) and i (20F) like the same girl (20F)

So i have one friend of group that have 5 people in it and only 1 boy which is the one who like the same girl as i am. Two days ago when he told me he likes her i feel empty , i feel like i should stop talk to her much idk too man. He likes her for 6 years and i only like her for 6 months he said he never confess to anyone because of her and he likes her so much but he want to remain the friendship with her so he try to move on from her right now but i know it’s gonna be hard for him to completely out of love with her cuz ofc we in the same friend group.

Idk if im overthinking or not but like me and her we really close not just as a friend we act differently depend on time. When we are with our friend we act normal but when there only two of us we flirt , caring for each other. And she the type of person who have high standard rarely like someone.

I have two decisions move on, forget about the relationship but gonna end up not knowing the answer or tell my best friend the truth before i confess to her.

Tl,DR: i still think he deserve her more than i am.