Dear Archie:
You wrote, “I’m so doomed”- well, you felt doomed when you wrote that, but you are not doomed. You can make a good choice in this situation, your world doesn’t have to crumble because a person sent you a message.
You have a girlfriend. If the relationship with your girlfriend is healthy and loving (is it?), keep it going and let the ex girlfriend know that you are involved with another woman.
anita