I used to suffer quite a lot from anxiety, and while it's still sometimes a problem, especially in new situations, or when I'm the centre of attention, it's nowhere near as debilitating as it used to be.
The worst period was when I started getting panic attacks. It only happened in social environments, which makes sense because my anxiety is centred around fear of ridicule. There was also an aspect of those panic attacks which was related to some previous bad experiences with drugs.
I got over the panic attacks completely, and greatly reduced my overall anxiety, through a few different methods;
1) Meditation. I believe this was the main contributor to my improvement. Being able to mentally and physically calm myself on command. It took many months before I noticed any improvement, but even since it's been getting easier and easier to approach that meditative state when anxiety starts to build up. Yoga is great too, though I only started that after greatly reducing my anxiety.
2) Journaling. Writing down how I've been feeling, and what caused those feelings, and what I did about it. All of this helped me to see the destructive patterns which were causing my anxiety. Ultimately it has turned out to be a lack of self-acceptance. I basically put myself down a lot, and ignored what really should have been clear evidence of my worth. In your case, you wrote out your issue here, and then you got the job you wanted. Sounds like it helped
3) Great friends. Without my friends I probably would have got worse and worse. No matter how easy or straight forward it sounds now, it's been a trial, and I have no doubt I wouldn't have made it without friends to reassure me, and to be there to talk through some of the things which journaling didn't help with.
4) Encouraging environments. Join a social group that involves performance of some kind. I took up swing dancing and tango. In both cases one has to perform well, and your partner could look down on you if you screw up. Of course he/she won't, but in my mind they could, and that's all it takes.
However, social dance classes are generally incredibly encouraging environments. No matter how bad you think you might screw up, you'll only get encouragement from the instructors and other students, because they've all been there before. It's a great environment to learn that it's ok to make mistakes. Another option is Toastmasters.
Feel free to ask me about my experiences if you want more details.