There are so many movies and songs about love, about being in love, about losing love. So many talk about how great it feels while some talk about how awful it is when you lose someone you love.
One particularly side of love which I think doesn’t get a lot of attention is one-sided love. When you love someone but they don’t love you back. There are a couple of songs and movies about this topic, but on the whole it’s accepted that both parties are in love or in love at some point in the relationship.
However the pain caused from rejection of a one-sided love I think is worse than the pain of a break-up.
I think it causes you to judge yourself harshly and wonder why someone doesn’t share your feelings. You wonder what’s wrong with you. And those feelings of love are difficult to shake. 
Of course if you do truly love someone then the best thing you can do is let me find their happiness even if that means without you. But the pain is quite real.
You can lose all your motivation and have no desire to do anything. These feelings fade and you realise that person wasn’t right for you. You slowly pick yourself up and carry on. But it’s a terrible sting that never gets any easier.