Most Helpful Guys
You've once had cherished memories with them that you didn't want to let go but had to for both your sake. It's painful to break it off with someone if you truly loved them; it's even more painful when you wanted the relationship to work but they refused to change for the better. If you never cared about them in the first place, you wouldn't be feeling any kind of emotional pain after the break-up which isn't the case here.
It's ok to feel emotionally hurt; it just shows how much you enjoyed and loved the good times in the relationship while you embraced them. Take in the knowledge you learned from your past relationship and make the next one even better! It'll take time for you to emotionally recover but eventually, all will be well again!
Most Helpful Girls
It's just damn hard. You got with this person because you saw something in him/her that resonated with you. Even early on you can have such hopes that you've found "the one". Then things happen for whatever reason and it's just very difficult to not be disappointed after it ends. And the longer things last, the harder it is to let go of what could have been or what you had hoped would have been. Even if you're the one who initiated the breakup.
Just because you've ended the relationship doesn't mean your feelings for that person magically go away. Break-ups hurt whether you are the one who initiated it or not. That's just the nature of them. Even if you know it was the right decision, it may take a while for your heart to catch up to your mind, and that's okay. It will just take time to start feeling better.