My ex gf (30F) broke up with me (29M) hours after telling me I "really mattered" to her

Forgive me in advance if this gets long. Writing it down is honestly the only comfort I can find right now, in what is a moment of deep sadness for me. So please bear with me.

So.. I (29M, Spaniard) and my ex gf (30F, British with Eastern European roots) met about 7 years ago, we were studying in different cities. There was some kind mutual attraction, but the distance meant nothing came of it. We kept it touch but life took us in separate directions.

Last year I reached out again. We started writing long daily messages, every single day, for two months straight. She looked very interested, kept asking me questions, was eager to meet. So we met in person, I travelled to her city to be with her, and I even relocated partly with the hope of getting to know her properly and build something.

Some context about her. She (by her own admission) has a terrible relationship with her parents and her own emotions. She's a very closed person in general: guarded, emotionally reserved, hard to read. Last year she ended things with her long-term fiancee, the man she was supposed to marry (they broke up 2 months before marriage). She also had an actual list of requirements for her ideal man. At some point I realized that a lot of the questions she'd asked me came straight from that list. And honestly, while being fundamentally opposed to the idea of bucket lists in human relationships, I ticked basically every box.

She's much better off financially and career-wise, whereas I was the "passionate" and thougtful guy. But I always tried to meet her halfway, to compromise because I wanted to build something lasting with her. She kept saying these "good things take time", but the signs were good. Just the other day we had planned a romantic getaway in Spain together (she even suggested a very romantic place!), just the two of us, by the sea, maybe a night out watching the stars.

Even the day before it ended she was saying affectionate things to me. You could tell it didn't come naturally to her, that she was making an effort, and to me that made it more genuine. That last night we made love and fell asleep in the same bed, wrapped around each other, her face on my shoulder.

Then the morning came.... and it all fell apart. It was a small argument, partly because she was in a hurry (she had to leave for work) and I was eating too slowly. From that little friction she said she didn't think we were right for each other and that our characters "are too different."

I'm struggling badly with the loss, and it has pulled up a lot of older pain about my own worth, my career, and where my life is going.

Has anyone been through something like this? An ending that comes out of nowhere, from someone who was in your arms a few hours before? How did you make sense of it?

TL;DR: Reconnected with a girl I'd known for 7 years, moved partly for her, ticked every box on her ideal-man list, we'd just planned a romantic trip, spent the night together, and the next morning she dumped me over a tiny argument, saying our characters are too different.