I see a lot of negative comments about short guys on here, mainly from short guys themselves. They blame their lack of success with women on their lack of height and they think that they're completely screwed because of it. I'm calling bullshit.
Women do tend to prefer taller men. That's just a simple truth that you have to accept. However, if you are short it's not the end of the world. I'm 5'4" myself, and while I'm sure that many women see that as a deal breaker I've never had trouble finding women who were interested. Most likely then it's something else about you that prevents women from wanting to date you, and these things can probably be fixed.
The number one quality that women look for and find attractive in a man is confidence. The reason my height has never held me back is that I don't even think about it. If you obsess over it you're going to become insecure and bitter. If you assume right off the bat that a woman isn't going to like you because you're short that will show itself no matter how much you try to hide it. It will show through your body language and the way you talk to her, and it will immediately turn her off. My only advice there is just to stop worrying about it because it does you no favours.
On the flip side, some men like to show how confident they are despite being short by emphasising it. They like to make self-deprecating jokes - this also isn't a good idea. You shouldn't be ashamed of being short, but at the same time you shouldn't emphasise it because it is an unattractive trait and it's not a good idea to draw attention to it. You should be working to your strengths instead. Smart people emphasise the traits that others find attractive, not unattractive. Talk about everything besides your height.
Sometimes others will make negative comments about your height as you know already. The important thing here it not to get rattled. See it as a test of your confidence, which women tend to do often especially in the early stages of dating, whether they're conscious of it or not. If you stay cool and you seem like you really don't care you pass, if you get upset, angry or defensive you fail.
There are also things you can do to make yourself look more physically attractive. The number one thing is to get in shape, particularly through lifting weights and building a more athletic/muscular physique. In America over two thirds of the population is overweight, and most other Western countries are close to that too. Of the remaining third, the majority are skinny and still our of shape. Being in shape gives you a huge advantage over these guys. Now many women will claim that they don't like muscular guys - what they mean by that are the steroid freaks, but even then those guys tend to do a lot better than the average guy. You don't have to be huge though, just don't be weak. Any guy who has gone from being skinny/fat to a more athletic/muscular physique will tell you that it makes a huge difference in the way women react towards you.
Posture is also important. Today most people have bad posture from a lack of exercise and from sitting on their asses for the majority of the time. A great way to look smaller is to walk with a hunchback - stop walking like you don't want anybody to see you and start walking like you're 10 inches taller than you actually are. There's a lot of information out there on how to improve your posture, and if done right you might be able to add an inch or two. I should also mention that if you do decide to lift weights as I mentioned before, make sure you follow a good, balanced routine rather than just working the beach muscles (chest, shoulders, biceps). Antagonistic muscles work together in balance - if you have an imbalance it will affect your posture. If you work your chest especially but you ignore your back, your stronger chest will pull your shoulders forward and you'll again be walking like a hunchback.
Clothing can either hide or emphasise your lack of height. It's even more important if, like me, you look younger than you actually are. If I wear the wrong clothes I look like a 16 year old boy. Wearing clothes with high contrast emphasises your lack of height because it creates a visual interruption, instead you should keep roughly the same colour scheme. Also you should avoid baggy clothing and instead wear clothes that fit you well. Some people also suggest lifts in your insoles to add an extra inch - I'd say that you should avoid those. They're not good for your feet, and it you date the girl long term she's going to see you with them off anyway.
So to sum up, yes being short is a slight disadvantage but there are plenty of ways to increase your chances of success. If I've done it so can you. Stop complaining, stop worrying about it, lift weights, improve your posture, dress well and play to your strengths. No more excuses.