Stop feeling sorry for yourself. Just because you aren't outgoing doesn't make you antisocial or shy, and 'always thinking about yourself'? Please! An extrovert is someone who likes to be social. If an introvert wanted to be social, then they could. Here are my responses to what you wrote:
1. Introverts enjoy their lives, but they choose to enjoy them alone. Having twenty friends doesn't mean you're any happier than someone with one or two friends. Some extroverts aren't happy at all, because their friends are just fake friends.
2. Introverts solve the world's problems. Extroverts can talk all they want, but introverts can listen and observe, and, what's more, they take time to think. Most likely, if we ever stop chopping down rainforests, stop terrorism and world hunger, and repair the ozone layer, it'll be the introverts who thought it out, because they listened, saw and thought.
3. Being surrounded by friends makes extroverts confident. Being alone makes introverts confident. Being an introvert doesn't mean you have low self-esteem or are pessimistic
4. There is plenty of place for introverts! What would the world be without all the great thinkers, artists, poets, authors and musicians that were introverts?
So in my opinion, if people like socializing, then they should socialize. If they don't, they can still be successful, confident, happy people. Parents shouldn't try to drag their kids to parties where they'll feel awkward.