Help me understand this man

I honestly just need some outside perspective because I am in total shock and experiencing the worst emotional whiplash of my life.

For the past 6 months, I was seeing this guy exclusively. We talked intensely every day, met up multiple times, and were planning a future together in Copenhagen. I fell so hard for him. Just two weeks ago, he wrote me this beautiful, deeply caring letter about his feelings for me. I felt so safe and happy.

Then out of nowhere, the switch flipped and he abruptly ended things. I was completely blindsided.

At first, he gave me these superficial, clinical reasons. He claimed a big factor was that our "senses of humor" didn't match and that we weren't laughing at the same things. I was so devastated and confused, trying to understand how someone goes from writing a love letter to breaking up over jokes. I honestly spiraled thinking there was another girl , because he aggressively deleted all of our photos and chat history to "cope" but kept her followed on IG

When I finally called him out and demanded real honesty, his wall completely collapsed. He dropped some heavy confessions that rewrite the whole relationship:

 He literally told me: "I don't know what love feels like. But it's possible. Was it infatuation? I don't think so but maybe I'm wrong."

 He admitted his career isn't why he’s always been single, saying "Other people with careers have someone."

 He told me: "Why do you think I have never been in a relationship? There are many reasons which I'm not sure you're seeing yet... Instead of you losing me I think you dodged a bullet."

Even though he tried to act so cold and logical at the start. He admitted he will never forget me and has to actively avoid listening to my favorite songs because they'll forever remind him of me.

I am just completely reeling. How can someone participate in a deep connection for half a year, write a loving letter, and then confess they don't even know what love feels like the second things get real?

Is this a textbook case of a severe avoidant attachment style panicking and self-sabotaging because of commitment? Or did he just lose feelings and use his internal issues as an easy exit strategy?