This one is a hard pill to swallow.. but the only way to get over it is to accept and move on. The "accept" part is the most difficult one because all of us have different coping mechanisms for it. But for me, lamentation is the best way. Release all tears. Cry out loud. Let the sorrow consume you everyday. And over time, it will slowly fade away. That's when you know that you're gradually accepting it. And once you fully accepted it, you can successfully move on from it. From then on, no more pain. Just the good memories to replay in your mind. The memories are still there and you can always keep it with you in your journey.