You died of cancer. Your husband promised he would love you even in the next life. He drank poison and followed you into death.

But when he was reborn, he forgot you. Haunted by the agony of his past life, he was driven into madness. Exhausted and broken, he chose to see his fiancée as you—because the pain was too much to bear.

━━━━━━━━━━━━━━━━━

I made two versions: the first one leans more toward fluff, while the second one is a bit more anxious.