It hurts

It's crazy to me how you love someone so long, pull through make it work, and then you just walk away. I understand people fall out of love, cheat on eachother, or hurt eachother in other ways. This process of relationships just sucks, everyone says you'll be fine and in time you'll get over it. But i love him. with all my heart. I won't call him and beg and plead to get back together, I did this so he can have a better life, but I'm entitled to being hurt, to having my heart broken, it's natural. If i walked away and didn't feel hurt, angry, or any kind of emotion then thats when there's something wrong. ugh, but why does it have to hurt soo bad