One of the hardest things to do in life is to let go of a relationship. No matter what the cause of a breakup, learning to let go just often isn't easy to do. It could be the one that got away, a first love, a spouse, a boyfriend or girlfriend, or unrequited love. Regardless of the situation, learning to let go of what's over is often a very difficult thing to do and the hurt can often last for years if a person simply won't break the hold.
Recovering from the horrible pain and hurt of a broken relationship is no easy task. When love is found, one naturally wants to believe it will last forever. And it's great when it does. The person might find themselves attempting to contact the other person, making up reasons to be where the other person is, calling them repeatedly, etc....anything to keep in contact with the other person or have some kind of hold or attachment still with them.
And while it's a natural thing to want to do this, it prevents us being healed of the relationship. In order to let go and live again, the past must be closed. It is impossible to live in the past. You can't look forward to a future when you live in what was, rather than in the here and now. What has happened is gone, and no amount of wanting, wishing, or regret will undo or changed what's already happened and is over with. To put closure on the past, you have to let go of the feeling that you can't make it without the other person.
Feelings of failure, trying to contact the person (unless you have children together), dependency, guilt, resentment, and anger... all of these feelings must be dealt with and brought under control. While they are normal to feel, continuing to harbor them keeps you from being healed of the hurt, and therefore keeps you from living and being happy again. Often when a relationship ends, one or both parties have the mindset that they are a failure. They measure their self worth by whether a relationship lasted or died. One's self worth should never be measured by another person, but rather how they are. When you love yourself, you will learn that your self worth does not revolve around another person but rather is enhanced by the other person.
While there is just no way to magically heal the pain and hurting of a lost relationship, there are ways to help yourself heal. The main thing is that you have to allow yourself to want to heal, and not keep clinging to something that you simply cannot change.