Social phobia is very common illness. Since your disease is very disabling you should consult a psychiatrist who will refer to you a good psychologist. He will also evaluate whether medicines will help you or not. You surely need some help.

Hello dear, homesickness on moving outside the safety, security and comfort of one's family is a commonplace thing and faced by most young people at such phases in their life. Howsoever, with the details you have provided, social phobia does not seem to be the sole diagnosis, having had stayed away from family for three years in a hostel and completing your studies without much impairment, suggests otherwise. Also there is no account of your early childhood & adolescence to make a detailed diagnosis. Many a youth who come to Delhi for studying find it difficult to adjust here initially because of the gross changes in culture, lifestyle, attitudes of people along with so many other things. You need to find out the real reason for feeling hopeless so quickly by discussing openly your concerns, anxieties and fears with a psychologist/psychiatrist. There has been no mention of your attachment to family members, parents as the reason for leaving, so it appears to be more than initial homesickness. Kindly consult a psychiatrist for counseling to know yourself better and learn affective means of communication, confidence building and anxiety management skills. You can get back to the mainstream in no time. Good luck.