To dream that people or objects are disappearing right before your eyes signify your anxieties and insecurities over the notion that loved ones might disappear out of your life. You feel that you cannot depend on anyone and that you will end up alone. You need to work on your self-image and self-esteem.
Alternatively, to dream that someone is disappearing suggests that you may not have given sufficient attention to those aspects/qualities of that person within your own self. Have you lost touch with some aspect of yourself? If your lover is disappearing, then it suggests that your love or interest for them is fading.
To dream that you are disappearing from others means that you feel you are being overlooked. You are not being noticed or recognized for what is important to you. Alternatively, the dream indicates that you are trying to withdraw from the realities of life.