Sounds like a good approach to RC. From my experience it never happened to me no matter how vivid dream I had. I can always tell when I ask myself if this is reality or dream. Try to calm down and focus on how you feel in the dream and normally. There are certain differences not only around you but also in your head, in the feeling of living or how to call that.
I actually think it is serious if you cannot distinguish dream and reality. It might be dangerous.
On the other hand I admit that we perceive the world through our senses that are connected to our brain where the picture, sound, smell etc is made and interpreted so basically there is not a big difference between dream and reality in terms of processing the surrounding world (dream or not) inside our head. The brain is not dumb though so it can tell.