Everyone has a few on their friends list and you might be surprised if you discovered who they are. "Friendly Acquaintance" is NOT the same as an actual friend. Few seem to know the difference these days.
You fall, love, learn, and then let go. Their part in your story is over, accept that and move on to the next chapter. You never know what will come next, that can be scary, yet, exciting at the same time. That's okay, though. Be brave and know in your heart, it'll be okay.