Difficult one this nick, I have always been a bit of a scaredy cat underneath. When I got promotion at my job I had to speak out to the bosses and staff, generally get them to accept me. I thought, shoulders back, you are just as good if not better than they are, and once I got used to the feeling of being one of the team and accepted I was fine. Don't try too hard to impress just begin by passing the time of day with people, Gym work will help you build confidence in the way you look and feel, and so too will making changes to your style. Good luck