It’s harder to move on after her “closure”

It’s harder to move on now

I found her version of closure to be incredibly unhelpful for me to move on. Just six days after we broke up, I discovered she had made a Spotify playlist with another guy. That felt like a punch to the gut. What makes it worse is that, initially, I was okay with the breakup because I believed we both agreed it was necessary to prioritize our studies. She even mentioned she had flunked a major subject, and I thought we were on the same page.

One night, I couldn’t hold it in anymore. I wanted to know if everything she said was a lie or if she had cheated on me. When she unblocked me, we started talking again. During the conversation, I realized something that made me furious: she only became straightforward about her issues with me after we broke up. I immediately thought, “Why are you telling me this only now?”

She admitted she used the other guy as a distraction and felt "guilty and embarrassed" about it. But what really stung was when she said, “I’ll raise my standards after you, no offense.” It felt like a slap in the face, and I’m still trying to process it.

What do you guys think? I don't buy that she "wasn't close to him before" and "only started to like the guy soon after we broke up"
I really hate that she never told me her problems. Was this planned?