There are effective treatments. Start by talking to those you find less attractive, and work your way up. View the information and weblinks for social anxiety/shyness, and self confidence, in sections 9, and 38, at http://www.ezy-build.net.nz/~shaneris Here is an exercise that can help you. It is called "Act as If." When you are in a social situation, act as if you are outgoing. Talk more, smile at everyone, ask questions, speak in a normal or excited tone, not a meek tone. Watch some of your outgoing peers, and imitate the style of their social behavior.
Research shows that when you "act as if" continually, your image of yourself begins to conform to your new behavior. In this case, you will gain self-esteem and self-confidence, and begin to see yourself as socially normal, not shy. You will become more socially successful, and this will motivate you to continue your new social behavior until it becomes a habit. Try this for a month, in every situation you can. I am confident that you will become much more comfortable and outgoing. One form of therapy is to go somewhere that nobody knows you, and deliberately make an utter fool of yourself: put on a paper hat, and scream out: "I'm queen/king of America!", or something else ridiculous, then get back in the taxi, (warn the driver of your intentions, first) or car, and leave.
People will point, and say: "Look at that idiot". But, you're probably not up to the stage where you can do that, yet (I can, and I used to be shy). It will teach you that, although it isn't actually pleasant, you will survive; be stronger for the experience, and the next time (should you need to repeat this type of therapy) will be considerably easier. Remember: "A fear avoided is a fear strengthened; a fear faced is a fear reduced." Regard it as your final test: once you have accomplished it, the barrier will be broken; just don't go too far, the other way! Learn to laugh at yourself, and give a big, cheesy grin when others see you do something foolish, as we all do, occasionally. It is endearing, if you don't do it too often. Use positive affirmations: for example: "I am very likable and other people feel comfortable around me".
Write down all of your self limiting beliefs; then write down the positive counter of them, (exact opposite) and repeat them and imprint them into your mind.
Most importantly: Force yourself to approach somebody and initiate some sort of communication. Start out small by asking the time and directions and gradually go bigger.
Although there are anti-anxiety medications (anxiolytics) available, these come with risks, and the possibility of side effects, habituation, even addiction, and withdrawal problems, and are unsuitable for young people.
Try having a cup of "Tension Tamer", herbal tea, by Celestial Seasonings, (from supermarket tea, or health food aisles) or make some at home, and cool, then bottle, and drink as needed (I find it so strong tasting, that I need to drink it quickly, followed by something like fruit juice, to take away the taste, but others may find it more tolerable). C(h)amomile tea is a more palatable option. As with all herbal/green teas, use lemon/lime, and/or a little sweetener (NOT ARTIFICIAL!!!) but no cream, or milk.
Xylitol, or Stevia is preferable, (health food stores) or fruit sugar (fructose, such as "Fruisana", from supermarket sugar aisles) or even a little honey, because these will reduce "sugar spikes". Valerian has also been recommended, but some people experience "valerian hangovers". Ensure you know how you react to it, before doing something potentially dangerous, like going out on the roads. The idea is to use the above like water wings, to provide initial, short term support, while you become proficient in the above techniques.