I like to think of it more in the terms of something you realized wasn't good for you, so the break-up was needed for your own benefit and health - which, by the way, is absolutely okay.
It doesn't make it any easier though. There are days you'll have to verbally remind yourself that hey, it didn't work out and now it's time to focus on me and my heart.
There will be days that memories will come knocking, yes. Gravity won't help stop the flow of tears. And everything will blur in a puddle of pain. There will be days when your heart is physically hurting and you think you're the only person in the world who has felt this sort of agony.
Trust me, it won't be an easy road. You loved and you lost. You opened yourself up to something that you thought would last, something beautiful that you thought would bring joy upon joy, but it didn't.
And you're hurting.
And that's okay.
And this is how you will let them go...
1) Look over all the pictures you took together
This will not only be painful, but it will also be good closure. You'll remember the good times, the good memories. And after looking at each picture, click the "delete" button. Trust me. It's for the best. You're letting them go with each one you erase from your phone. And it's okay.
2) Listen to the songs that were once "yours".
These songs hold old memories, but now it's time to make new ones with them. Don't let the past dictate your future. Cherish the old, but don't be fearful of creating the new.
3) Travel down memory lane.
Whether mentally or physically. And yes, it's okay to think about the not so good memories too.
4) Stare at your phone when they're online and hope they message you first
There will come a time where you'll just have to stop this. And if deleting and blocking them is what's necessary for this to end, then do it. Remember: it's over, and it's okay.
5) Forgive them.
It was a privilege to love them, wasn't it? But it was also freeing to let them go. Both choices shaped you into the person you have become and they were both good choices. Forgiveness is more freeing than holding any sort of resentment against them. Letting them go by forgiving them.
"I will forgive you for being so perfectly flawed that I see you so perfect for me; damaged and broken... For what it's worth, I do not regret knowing you at the time I am most vulnerable. You are a beautiful person whom I met at the wrong time. Someday, everything will make sense for both of us. If we cross our paths again, I will look at you with no self-loath; no pain. I will smile to you and not hate you, I promise. I will do that because I am better without you; that, we both know."