I was a big coward in the same respect. So I made it my career.

Here you go. Crisp straight Easy steps to achieve fluency. If you follow, you're good. If you don't, get ready to post the same question on some other site. ;)

• Anxiety is a natural outcome of lack of breath control (It may seem off track but it's not. Till the time you'll reach end of the answer, you'll know why I said so) and best way to control it is Pranayama. Watch an Art of Living or Patanjali youtube video for Kapalbhati (a), Anulom Vilom (b), and Udgith Pranayam (c). Spend 5-7 min on a & b and 2-3 min on c. Afterwards, Sit with eyes closed for 10 minutes (Meditation). In few days, you'll start feeling a new boost of energy that won't let you fear of anything.
• Read a lot. Reading has dialogues and thought processes. Start with easy books and go complex thereafter. Some books to start with are Catch22 Joseph Heller), The Immortals of Meluha(Amish) , The fountainhead (Ayn Rand)
• Talk to people in English. Be it customer care, select English; Be it Mc Donalds, Use English; Go to the temple, Wish or Curse in English (Don't worry, God understands every language); In small group of friends, Speak in English. DO NOT WORRY ABOUT OTHERS THINKING WHAT OF YOU. It's no less than a panacea. V Imp.
• Download a voice recorder in your phone. Now imagine a girl or any influential person is there. You have a subject at hand (Say ,Theory of relativity or any Newspaper column), and explain it to him/her. Do this for 10 minutes in the beginning while everything is being recorded. Now listen to that recording and you'll know where to improve.
• GRAMMAR can be a great concern. Use Guide to Grammar and Writing for it in addition to reading books.
• Watch TV series/Movies with English subtitles. (Manage your time accordingly). I'll recommend that you start with FRIENDS. Watch discovery Channel, national geographic, etc in English. Again V imp.
• Use twitter. Say whatever you want in 140 characters. It will change the way you communicate.
  

Just don't worry. It will TAKE TIME. DO NOT HURRY. give yourself 2-3 months to notice a considerable change.

PS: To boost your confidence, I've found Art of Living's Sudarshan Kriya Very Effective. You can learn that in any Art of Living Happiness program near you.

Source: I'm a soft skills and English language trainer with Ericsson, NIIT, and Career  Launcher.