She 20f broke up me 24M and got with the guy I was told not to worry about - subject of our last argument

I am in South America and I met this girl from Center Europe at the end of the last year.

We were having bad moments since february, when she threatened to break up with me a few times.

She then decided to go to her country's capital in order to watch a concert. We were worned out at the time, but still talking.

On the next morning, she met with her best friend, still in the capital, where this friend brought a guy friend of hers.

My then girlfriend met him and "they became friends". He asked her out for dinner, and she stated that she didn't want that because she already had me. Even so, she kept being friends with this newcomer, under the argument of him respecting her and she having liked to be friends with him.

She was being dry to me, as she had been for the last months, and two days after she met this guy, I asked her whether she had found someone new. She came up with "I found, a friend". It was when she told me this whole story.

He was the only guy friend she made during the relationship.

On my end, I was bothered that she only told me about this two days later, and I had to ask her. I was suspicious, my gut was telling me that something was... wrong.

We argued over this. I went over the line and said "then get with this guy and leave me" since I was infuriated with the whole lore.

She broke up with me, saying she'd love me forever. She then went dry, asked for NC. Okay. I was fractured. I had loved her.

Faster forward one month and a few days, she gets with this new guy. From what I could see on ser socials, she's already posting about marrying and having children with him.

I really don't know what to feel. She told me she'd love me forever. One week prior to setting herself up with him, she told me she wouldn't get with anyone, if she could.

She did want to move on. She stated this. She had no plans of coming back to me. I talked about it her two days, asked her if she had found someone, then asked if it was the guy with whom we had our last argument over. She told me, no. I had proof that it was him. She's saying she had forgotten and then apologized and said that right, it was him. **She had the audacity of saying she didn't remember telling about him to me**