My World Began With You

Most people would think of Immortality as a gift, but Elena thinks of it as a curse. She has been alive for a very long time and is immortal. She sees no purpose in her life. She seeks to find a way to pass on because she can't bear being alone anymore. Will she actually succeed or will she find someone that will help her find the strength and will to live? (Truthfully I think the actual story is better than the summary. I'm bad at making good summaries...)