What if I don't have a dream?

I always think about what I want to be. Yes there are many options nice jobs but I can't seem to know what I really want in life. If someone is going to ask me "What do you want to be or what do you want to do after you graduate?". I will say "I really don't know". It's so hard specially I'm not an extrovert person. I'm a very very shy person and I don't like going out I just like to be alone in my room. and I'm scared to meet  new people. That's why I ask myself "Will someone hire me if I'm like this?" the answer is no. and I don't know the things I enjoy cos the things I find interesting before is not enjoyable for me now. I don't feel happy about the things around me anymore. When I'm alone in my room I feel happy I'm not pressured, no one will judge me or say bad things about me. no one will say I'm dumb or stupid. I'm not smart and I'm a slow learner. well there's just two things I really like doing. studying English and Singing. I like to study English subject even though I know my grammar sucks. and I like singing even I'm not so good I find comfort with it when I feel sad it helps me express my feelings. Last year I studied Business Management but for the past 5 months that I stayed in Uni. I didn't have any friend. In class no one wants me to be in their group so I always study alone. I eat alone I go home alone after class. then September 2012 after my birthday I ask mom that I don't want to go to school anymore, so I stopped. I feel so down, so hopeless and sometimes I think about suicide. thinking that there is nothing good about me. It's so hard especially even if you explain yourself to someone they won't understand you cos they don't know what you're going through. they will only judge you. Thinking you're crazy, Insane. I hope one day I'll find the answers to my questions.