I keep seeing how my best friend died... she died in September in a horrible train accident.. and I keep seeing how it happened, and then I see flames because she was creamated... and then at the end I see red, black and white roses at the end of the dream, the same ones I left at her funeral.. and if I don't wake myself up by the end of the dream, it keeps re playing.. what does it all mean?.

It sounds like your unconscious mind is simply on a merry-go-round ride through all the memories surrounding your friend. I don't think there is any "meaning" to be gleaned.

Your friend is probberly wanting you to understand her death more and wants to no that you no , she tells you this by making you dream certain things, she just doesn't want to be forgot and by you dreaming like this shows you worried and miss her , just try and let things go abit and try not to think about it too much and your dreams should go back to normal.