At times, you need to wait for the person you love to love you back. It's not always right to impose yourself on them or letting them go. Letting them go would mean ending everything which is really hard. And imposing yourself on others would be hurting them, hurting the one you loved which obviously is not what you really want. So all ypu need to do is sit back, wait and impress him/her. You need to prove yourself, you need to prove how much you really love the person. Make the person realize of your feelings but never impose yourself. Never try to harass her in the name of love. At times, you need to wait. And even she/he doesn't accept that'd be wrong for herself-you'll be losing a person who never loved you, but she? She/he'd be losing a person who loved her/him, cared for her/him, could do anything for her/him.