honestly, it just sounds like another weird dream that the brain ended up manifesting. brains just grab at thoughts/memories/ideas and try to see things through + process things, resulting in a dream (do not take my word for it, im no expert). i dont think it really needs to be looked into too deeply, but if you would like a deep answer: maybe it's a warning or maybe it's trying to tell you that there's something in your life stressing you out. maybe the rollercoaster was to symbolize your life moving too fast or changing too much to where your crying symbolizes that you're distressed with the change or smth? idk, but that's my deep take on it. i still do think it's just another random dream you ended up having, like all dreams, but who knows! i could be wrong!