Unrequited love is a loss.
It is normal to feel grief, anger, denial, and all the other things a person might feel after loss. Your feelings about the person you love are real, and the hopes you had had are real.
In our culture, we don’t give space to mourn the loss of unrequited love. We tend to say either “Go get ‘em, try harder, your love will win out eventually!” or “Stop being pathetic and get over it.”
And neither of these are healthy