There are a lot of things you can do to cope with culture shock:
First and foremost, know that your reactions are normal and that you can talk about them with other people.
Stay in touch with your family and friends back home, but do not spend all your free time sending emails to them or reading your local newspapers.
Make friends with other people. Although it will be comforting to have some friends from your home country, try to make friends with people from other countries as well. It will enrich your expatriate experience.
Get some physical exercise. For many people sports is a good way to stop worrying.
Find shops and restaurants that sell food you are used to at home.
Get out of the house and do something. Look for some suggestions on the Living and working in Melbourne page.
And, most of all: enjoy yourself! You have the rare privilege of living in a foreign country and experiencing another culture - it will certainly be a memorable and valuable time in your life.