First of all, because of infatuation, it proves that you love her very much, that is to say, she is already an indispensable one in your life. When the relationship is over, it's hard for you to let go, so you will get hurt. Because you put too much affection on her, when she slips away from your emotional world, you will feel uncomfortable or lonely and empty, and even feel that life is meaningless, so you will get hurt.
Secondly, no desire is just. Can you hurt someone who has no feelings or thoughts about you? Only when your feelings and thoughts are not satisfied can you be hurt. She can hurt you, which shows that you have a deep attachment to her. Maybe you will think about how much she loved you before, but I'm telling you, maybe someone used you for a show. When you are worthless, she will leave you, but you are miserable.
Finally, advise those spoony people to let nature take its course when your relationship is over and you can't stay. Because feelings can't be forced, why put too much pressure on yourself and ask for trouble. Although it will be painful for an infatuated person to leave you, you should know that an infatuated person just wants to make the person you love happier, and maybe leaving is her happiness. Infatuation is better than impetuousness, because for an infatuated person, he would rather be hurt by himself than by others.