After Withdrawing My Confession, I Could Never Love Anyone Again

I wrote about my secret crush in a diary and set it to become visible ten years later.

One second later, I was sent straight to his wedding. The bride was me.

System prompt: As long as I say, "I never loved you," he can live, but I will lose the ability to love forever.

One sentence to trade for his life, and a lifetime without love for me.

Can you guess what I said in the end?

This novel and its characters are entirely fictional. Any resemblance to actual people or events is purely coincidental. Do not imitate.