Some pain shouldn't be wished away so easily. It had to be dealt with, even embraced. Without the agony of the last few months, Piper never would have found her best friends, Hazel and Annabeth. She never would've discovered her own courage. She certainly wouldn't have had the guts to sing show tunes to the snake people under Athens.
As much as I cared about him, I wasn't a slave to fate. I could choose to ignore my feelings, strong as they were. It would be painful, but no more so than letting myself pine for my friend.