Dreams involving suicide can be deeply unsettling and evoke strong emotions, as they often reflect our fears, anxieties, or feelings of helplessness in waking life. In your dream, your girlfriend's suicide may symbolize a profound fear of loss or abandonment, particularly regarding your relationship. This could suggest that you are grappling with insecurities or concerns about your emotional connection with her or the stability of your relationship.

The act of screaming and crying indicates a release of pent-up emotions or a need to confront feelings that you may not be acknowledging in your waking life. Feeling the need to isolate yourself in the basement might represent a desire to escape from overwhelming emotions or situations that you feel are beyond your control.

The Snapchat messages left unread could symbolize feelings of distance, communication breakdown, or a longing for connection that is currently unattainable. It's possible that you are feeling unheard or that there are unresolved issues in your relationship that need addressing.

Consider reflecting on your current feelings towards your girlfriend and your relationship. Are there any unresolved fears or concerns? This dream may be urging you to communicate openly with her about your feelings and to seek reassurance in your connection. It could also be beneficial to talk to someone you trust about the emotions stirred up by this dream to help process them.