Caroline
Few years back, I'd have told you yeah - just being a vampire would have made you a monster in my book. But, y'know, it's not really like that. My sister in law is a demon. I don't think she's a monster. Usually. I don't really know you that well, bu I can tell you if you're worried about becoming one, and you're this upset over it, you aren't. If you care, at all, you're okay.
It'll get better. Not right away, but it will. Just... hang in there. Don't push people away, especially not people close to you - even if you're scared you'll hurt them. I've tried that... it doesn't help. It just makes it easier to give in, the more alone you are.