"Someday everything will make perfect sense. So for now, laugh at the confusion, smile through the tears, and keep reminding yourself that everything happens for a reason." Even if someday it doesn't make perfect sense, it happened for a reason.
The person might not be who you thought they were; might have changed for the worse; but in the memories, they will always be the person you loved. it's ok to cherish those memories. You dont have to allow that person in your life now.