Indy, it's hard to know what to believe. I suggest you use other people's experiences and stories as road maps. There are many roads to the same place. Yours does not have to include astral vampires if you don't want it to. Use our experiences to determine your course.
I don't believe in Hell. And once you vibrate at a higher frequency (like around love, joy, peace, and compassion) the dark, negative beings can't reach you (unless you let them).
Read this article:
Erin Pavlina’s Blog » Blog Archive » Does Hell Exist? Does Satan Exist?
And this one:
Erin Pavlina’s Blog » Blog Archive » How can we attract the good spirits without attracting the bad?