Once I Was His Mistake, Now I'm His Regret

The biggest mistake I had ever made was falling in love with my Alpha stepbrother, Cayden Gates. I was 12 when my mom remarried, and he was the only one in the new pack who treated me kindly. I fell for him at first sight. When I was 16, I was attacked by rogue wolves, and he fought off ten of them alone to protect me. At 18, he was poisoned by silver. He nearly died. That was when my wolf told me he was my fated mate. Without hesitation, I donated my bone marrow to save him. That night, watching him asleep with a pale face, I couldn't help but kiss the corner of his lips. He opened his eyes at that exact moment, his face flushing red. "Tessa, we're siblings. You shouldn't cross that line." From then on, he started avoiding me, like I was a mistake he couldn't afford to make. His fiancée, Rosie Lloyd, had been diagnosed with a rare blood disease, and I was the only compatible donor. For the first time, he pleaded with me. "If you're willing to save her, I'll agree to anything." But I was already weak from the marrow transplant. Giving blood again might kill me. I said no, and Rosie died in the end. He didn't shed a single tear, like nothing had happened. But at her funeral, he smashed the portrait I'd painted of him in front of everyone and said coldly, "How filthy of you to dream of being with your own brother." Later, I became a disgrace, a walking joke. Humiliation and despair swallowed me whole, and in a haze, I fell into the lake and drowned. When I open my eyes again, I'm back at the moment he begs me for blood. I say yes calmly. I consider it the final debt I owe the Gates family. Cayden, from now on, we're done. There are no more ties between us.