What is my best friend left me?

I am sorry to hear that your best friend left you. This can be a difficult and painful experience. It may be helpful to talk to someone you trust or a therapist to process your feelings and work through the loss. It's also important to remember that people's priorities and situations can change, and sometimes friendships may not work out. Take some time for self-care and reflection, and seek out opportunities to meet new people and make new connections.