Friendship losses are one of the biggest mental health problems people can get because friends are just a part of our lives and we need them all the time. You can't live without a friend. It's hard. It's just not explainable. It's not easy to understand that you lost a BEST friend and now your life is more different than before. You want to bring it back to the way it was before. If you have not lost your best friend yet, try to keep them tight to your heart and to you, and never let them leave.