I don't think you're scary at all, but remember that women can smell desperation a mile off, and it is not attractive at all.
My advice would be to try something like yoga, or other relaxation tecniques, before you go out, so you are calm, and give off the ora of confidence and not despiration. Perhaps have a little self anchoring routine to use in a club to calm yourself down a bit when she uses the restroom.
Also try not to think about the end result too much (i.e the number, kiss, sex etc) but keep your mind clear, remember what you are aiming at, but don't simply concentrate on that. As cheesy as it may sound, try to enjoy her company a little more, rather than seeing the whole thing as a challenge/chore. Then if she does just walk off, at least you have enjoyed yourself, and you can simply move on.
Remember you can have all the knowledge, but if your giving off the feeling that you are a little desperate, it simply might not work however good a PUA you are, so just relax,
Don't worry, it will happen, and when it does it will be like the floodgates have opened and you will need a bigger memory card on your mobile just to keep all the numbers in!
Have faith, you'll get there.
