Caught My GF of 5yr cheating on me !!

I'm M(23) was in a relationship with a F(23) for 5 long years (Long distance with 2-3 times meet in a month) Within those periods she did few stuffs which i didn't liked but but after a blocked her she promised me to not repeat such things again and we were in a happy relationship with small fights and all But couple of months back she joinend a liberary where she meet a guy (owner of liberary) They used to talk on whatss app calls and even used to meet within this period we had a small finght where we were not talking for a week but other than that it was going preey good But i had doubt on her looking at her social media interactions and sometimes her last seen used to be @2AM So today i thought l'll check her whats app And i caught her talking to him When i asked her abt this She started to play victim card as others girls loves to play I only love you so so much I had fear of losing you and i can't live without u and i thought l'll loose you so i needed someone's support so we started talking he's a frnd !!

Now my life will be fucked up !! Since it's been a hr only so l'm okay right now but with coming weeks I don't know how I'll move on

Moreover there was a convo with her female bestie abt wishing bday to her Ex But she told me he's blocked for years!!!

Should i call her new one and tell him the reality? After that he can do whatever he wants but atleast he knows her real face!