True, but sometimes it lets you identify the problem and actually solve it, rather than worrying about the unknown. The real issue is self-diagnosing or having someone who is unqualified diagnose you. It's easy to become a hypochondriac if you allow yourself to become fixated on a disease that you find... for lack of a better word, appealing.
Realistically, alot of people are shy and reclusive, but sometimes its a phase that passes. One thing I did to get better at being social (I'm not by a long shot an extrovert) is getting a job. I used to work at a Bed Bath and Beyond and I was forced to interact with customers and my co-workers. This sort of alleviated my anxiety because I had an excuse to talk to them.
Technique only.