I would start looking for a new job. While doing that I would take a hard look at how my behavior may or may not have influenced my coworker perceptions . If there is a coworker you do have a good relationship with, you might want to have a conversation about the situation. Might be painful but take what you learn to heart. This is but the first of a long string of jobs in your life. It is entirely possible that it is simply not a good fit and the next job will be more comfortable socially but with each job you will learn and grow.