Dreaming of being alone means taking time away from distractions for personal growth. You choose to step away from the daily grind and reflect on the things you have achieved to gain further insight of your life. It is also a time of rest where the body and mind can heal.
Alone in a dream means to be lonely and isolated from the rest of the world. Alone in a dream can be interpreted as feeling like you are not good enough for anyone else and that you are stuck with yourself and no one else will ever love you.