You are fearing that which you project onto others. You said that you don't dare talk to guys that you like... Uhm... Maybe it's because you are afraid of them doing to you what you are doing to those who are "ugly and short."
Sometimes we are our worst enemy. Internally, we can be catty, mean and nasty little bitches. We're like "good gawd, I hope no thinks of me the way I think of them." This kind of mind set is brought on because we are extremely judgmental of others, and we think that others are just as judgmental of us as we are of them, and fortunately, this is not always the case.
Try being a little less judgmental of others, and I guarantee you that you'll be less intimidated by people and will have an easier time talking. If you actually go into a bar with the mindset that "I hate everyone," then guess what? You're committing a self-fulfilling prophesy. You lost the game before you even started playing it, so why even bother going out. People can read your subtle body mannerisms, such as your arms and legs being crossed, your constant stares to the ground and the general off-putting nature of how you stand. Open your body up, smile and at least act like you like being there (fake it til you make it), and I promise you, guys will come up to you to talk to you. Hell, you may actually get to take one home for the night.