Don't try too hard
You have talked 2 or 3 times to the person you love to see if they love you back the same. They don't. Then what to do with them? Nothing. Just let go. Even if you madly, desperately love them, don't try to make them. Keep the mad love in your own heart. Don't drown the other person with your feelings. Don't try too hard.
You can't use logic to convince anybody to love you. You cannot charm them into loving you, against their wishes. You cannot force or make anybody love you, if they don't already feel the love for you. Moreover, convincing somebody to love you with your charm, beauty, money or sex is not the best way to
Walk away and keep away
The other thing you do when your love is not reciprocated is just walk away. Put some distance between the person you love and yourself. In fact, if you know for sure that they will never love you back, it is best if you don't run into them or communicate with them at all. At least temporarily. Perhaps later, when your heart has let go and healed, there may be a chance to resume some form of acquaintanceship or friendship. But when your love for them is still burning bright, when the wound of rejection is still fresh, when your heart is still hurting, any type of regular and/or close contact should be avoided.