Problems with my Bff :d

Hello guys. I broke up with my bff just yesterday, our friendship lasted 5 years.
She found another good friend recently, when i was gone in my vacation for a weak and we didnt talk. She wants him as a best. she told him these things " our friendship was wearing thin anyway
over the last year
its been more and more
boring
but..
shes my one friend
apart from you
well still acceptable
but not the same ". And I'm very jealous why didnt she try to solve that problem with me ? what did she do ? she found another friend. She didnt want to lose me either but i couldnt stand that. Was I boring when I was there for her ? Should she talk like this about our friendship with a stranger basically ?

I doubt if she'll forgive me anyway if i apologize, I doubt if I did the right thing when i broke up.. any opinion?

Ps: I don't know if i can stand the third friend . Sometimes I'm going crazy.
Everything since i returned hurted me so much . They even planned to talk behind my back

Hi Foxie and welcome to PC! I'm glad you found your way around.
I'm sorry your friend has been talking behind your back. Maybe the three of you could sit down and try and talk it out and see if there is a way to all be friends?
Good luck!