she left me for another guy

she left me for another guy and I never felt worse

Exactly 2 weeks ago,she left me for another guy.(We were in a distance relationship)She went to a party,before she went there she said to me how much she love me,how she can’t wait till I move in her city so our relationship wouldn’t be through the phone,how there’s no way she would touch a boy in that party…she went there and the next day she called me and said that she wants us to break up…I cried on the phone begging her not to leave me,but she was so cold,it felt like I was talking to a different person…she didn’t want to tell me the reason she wants to break up,and told me we’re gonna be friends.I love her so much that I can’t lose her so I settled for being friends…but she stopped texting me,stopped answering my calls,and removed me from close friends on Instagram…she continued to post stories,post tiktoks,and act like nothing has happened and like I never existed…Later her best friend told me that she has a new boyfriend and today I saw her on a tiktok live with her new boyfriend’s tshirt,laughing and smiling. She broke my heart,she was the perfect one for me and she completely removed me from her life without any hesitation…

TL;DR my girlfriend left me for another guy and I don’t know what to do.