gladgirl, I really hope that things will turn out good, and I can totally understand your unease. It's true subs are vulnerable and it's a tough choice to be submissive, to take on that drive, but to some of us, if you got it in you, it's really the only possible, the only fulfilling thing - I know Tessa would agree with me there: only when you're brought to your knees and used mercilessly by your caring, but hard Dominant does it hit the wellspring of your being, and you'll sob, smile and want more.
Don't give in, the Dom who will put you to pain, understand you and make you see yourself in a new light is out there.