woke up and in tears

I've just woke up from a horrendous Nd very vivid nightmare that one of my best friends from high school was raped and murdered. This has really really terrified me, I am so scared and can't get back to sleep. I'm not pregnant, my daughters 5 months old, although have been thinking I'm pregnant again and now I deff am convinced. I never have nightmares. Ever. What does this dream mean 😭😭😭😭😭😭😭 OMG it was horrible