When I was at school I always knew I would struggle if I had to interact face to face with many people each day when I entered the working world. Luckily I have the entrepreneurial spirit and decided early on I would create a job for myself by starting a business and becoming self-employed.
If you think you could see yourself running a business I would recommend looking into this while you are in education or already in a job as an alternative or something to work towards. If you have a talent for anything it is very likely you can make more money working freelance than working for a company.
Having said this, unless you have a burning passion early on it is always better to learn in the safe environment of being employed as you will benefit from knowing how your chosen profession/ skillset fits in to the economy and important things like understanding how the company finds clients, builds relationships satisfies their needs and makes sales. This way if you did decide to give it a shot on your own, you know exactly what you need to get started and possibly take some clients with you.
I am 31 now and have struggled with having SA and being socially inept for as long as I can remember and being able to run my own business has basically given me a much better quality of life. You get to live life on your own terms and chose to a large extent who you interact with, for how long, when and where.
I would also say that if you are young and get the opportunity, go to university as it will open up a whole new world for you and very likely make you feel a lot more confident with yourself and interacting with other people. I went to uni when I was 18 and there are all kinds of weird people just like you and me! You will definitely meet new friends who will help you deal with your SA. After this experience I guarantee a lot more jobs will be open to you and you can find a great paying career job to suit your needs.
Here are some ideas and places to look for jobs that might suit you:
Check out freelancing sites like Elance, Rentacoder, peopleperhour and freelancing forums. These sites collectively serve up a huge array of option for different jobs that companies are trying to get done by finding freelancers to do them. You can search their databases for projects that would suit your skills.
Virtual assistant – like an online secretary that carries out administrative tasks, writing, data entry but working from home instead of an office, and working for yourself
Look at all the things selling on ebay. Behind these auctions is an army of small businesses and one man bands selling products (and services through classifieds) they stock or may even just take orders for and get another company to drop-ship for them.
All these jobs are things you can do from your home. It may take time to get jobs and build up a portfolio but it will add to your income and enable you to earn a nice side-income doing something you enjoy or at least do the work in an environment you are comfortable with.