Struggling to find closure after a sudden breakup

My ex (21F) broke up with me (25M) about a month ago after a 4-month relationship/5+ months of talking every day. Things weren’t perfect—we both had relationship anxiety—but there was a lot of affection right up until the end. She had recently told me she loved me, talked about our future, and the night before the breakup was still being affectionate. Then the next day she abruptly ended things, saying she had a “list of anxieties,” didn’t think she could be in a relationship, and was afraid of eventually getting hurt.

There had definitely been signs that something was off. In the weeks before the breakup she became more distant, stopped engaging with music/things we normally shared, sometimes seemed suspicious that I was talking to other women, and canceled plans more frequently—including the night before my college graduation. She was also dealing with significant anxiety, family conflict, and some personal/substance-related struggles. I tried to give her independence rather than constantly chase reassurance, so I knew she was struggling but didn’t realize our relationship was apparently on the verge of ending.

What’s making closure difficult is everything afterward. There was never really a conversation explaining what happened. I was blocked on most platforms, she purged/privated a lot of her social media and playlists, removed things associated with us, and has made various strange online changes since. I sent one final letter returning something of hers, apologized for my own mistakes, told her what she meant to me, and made it clear she didn’t owe me a response. I haven’t contacted her since.

I know nobody here can tell me what she’s thinking, and I’m trying to accept that silence may be the only closure I get. I just can’t reconcile how someone could seemingly care so deeply about me and then disappear without ever acknowledging what happened between us. For people who’ve experienced a sudden breakup like this: how did you stop waiting for an explanation and create closure for yourself?