:o How do I learn how to do Presentations without panicking and to also participate in discussions without being shy

The key is confidence. Maybe try something like.. make up a mock survey and go to a shopping centre and interview shoppers about... well anything you want, you could even make it about public speaking! This will get you used to it, give you good social skills and an understanding on what kinds of reactions you can get and how to overcome your fear!
I hope this idea helped:)

Talking in Public is one major fear or worry within the youth of today!
With this One can have the confidence or setup a special goal that: when he or she does not talk in public today... he or she is going to loose his or her life after that... This is one major plan and way of achieving ones shyness @ wherever u found yourself... NB: U can make it... This method help me a lot...