Heartbreak question

Can anyone answer this question: Why is heartbreak so hurtful when it happens so much?

I feel like every time I open up the same things happen, I get too attached, I love to quickly, and ultimately get heartbroken. For years the same man led me on continuing to tell me what I wanted to hear just to get into a relationship with another girl. He told me so many things that meant so much to me and he threw it away like it was nothing. Its been a while but I feel like his presents are still haunting me. so someone please answer me this, why does something that hurts so bad mean so much to other people? Why is this the only way to find true love? Is it really worth all of the sleepless nights and heartbreaks to find someone who is gonna leave?