Dreams involving relationships, especially those that involve feelings of betrayal or loss, can often reflect your emotions and experiences in waking life. In your dream, discovering that your boyfriend is someone else might symbolize feelings of insecurity or fear of abandonment. The act of finding a stranger's ID in his wallet suggests that there may be aspects of your relationship that you feel are hidden or not fully known to you.

The intense emotions you experienced in the dream, such as scream crying, indicate that you may be processing deep fears or anxieties about your relationship. The statement from the stranger that your boyfriend "never existed" could represent a fear that your relationship is not as solid or real as you believed, or it may reflect feelings of disillusionment.

To gain insights from this dream, consider the following:

1. Reflect on Your Feelings: Are there any current insecurities or doubts you have about your relationship? It might be helpful to discuss these feelings with your boyfriend if you feel comfortable doing so.
2. Assess Trust and Communication: Dreams like this can signal a need for better communication or a deeper understanding between partners. Think about ways to enhance trust and transparency in your relationship.
3. Explore Your Emotions: Acknowledge the feelings that arose during the dream. Sometimes, our subconscious brings up emotions that we may not be fully aware of in our waking life.

Overall, this dream could be encouraging you to reflect on your relationship and how you feel within it. By addressing any underlying concerns, you can work towards a more secure and fulfilling connection.