I'm not sure we have the same understanding of vivid dreams, but I suggest you take a look at Lucid Dreaming which is about taking control of vivid dreams. There is a lot on the web on this subject.
I think it is next to impossible for one to bite him/herself while sleeping, that is contrary to the accepted "fact" that we all go into a physical paralysis when asleep, to prevent that sort of thing - so we don't turn crazy dreaming into self violence.
I am not saying it didn't happen, but that from the little I know it is very strange.
On Lucid dreaming, one should be able to control the fear generated in nightmares by "taking charge"... realizing we are dreaming and we can't be hurt by something in our dreams. Lucid dreaming theory suggest a number of way to confirm we are asleep, the "trick" it taking the step while asleep. In my experience that is accomplished by "programing" our minds to check often (am I awake) - see Stephen LaBerge Stanford University, his book on Lucid Dreaming was very enlightening to me.
I suspect you bit yourself and your sense of pain was not aroused in your consciousness because you were asleep when it happened. Try to remember your vivid dreams and self-analyze why you are hurting yourself.