This dream may reflect unresolved feelings and trauma from your past relationship with your ex. The fact that you haven’t spoken to him in over a year and a half suggests that you have been trying to move on and heal from the emotional and mental abuse you endured. However, the dream may be a manifestation of your fears and anxieties about potentially reconnecting with your ex. The fact that you started dating again and it was going well may symbolize your desire for closure and a sense of closure in the relationship. However, the appearance of your best friend and her interest in your ex may represent your fear of losing control and being hurt again. The drowning at the end of the dream may symbolize your fear of being overwhelmed and consumed by the negative emotions and memories associated with your ex. It may also suggest that you need to let go of this toxic relationship and move on in order to find peace and happiness in your life.