If the one you love doesn't love you back, or doesn't care for you the way you are for them, it might be time to let them go.
You are someone special, valuable, beautiful. You have so much love to offer. No one is worth wasting that on, even if in this moment they have your heart. Respect yourself enough to know when it's time to move on, and stop giving your love to a lost cause.
If they don't feel lucky to have you in their life, then they don't deserve you!