Hehe, these aren't too common really, just classify them as nightmares, I too had reacurring dreams when I was young (though I dontget them much anymore) I dont think theres much significance with the vampires and monsters except perhaps you have or at one time had an interest with the supernatural or were tramatized somehow or (The list goes on and on) Do not be afraid to go to sleep, in fact a lot of people practice Lucid dreamig to prevent nightmares, so the next time you become concious Change it. Its just a dream however, remember this, and over time you should find a way to overcome the fears and change your nightmares into dreams. (You can also telling yourself before sleep 'its just a dream' or 'I will have a lucid dream.')