I know how you feel as I have been there and to a lesser degree, still am.
We forget or are unaware how difficult it is to start over again, especially if we left a life where we had a decent job, a home, friends and family. We sacrificed routine and comfort for change.
Australia is at the other end of the world and is very isolated. It's not as if we can hop on a plane and return to Canada for a visit in 5-6 hours.
Personally, I was miserable and had such trouble adjusting the first few months in 2009 that at the 6 month point I returned home for a few weeks. This made all the difference and I looked forward to returning to my new home. I will go back for a visit in 2012.
Yes, it is a different culture. Some cities are a little more 'bogan' than others and/or quiet. At times it is not very sophisticated, insular and in a time warp of sorts; it is a society that works to live, unlike us. Work-wise, unless you live in Melbourne or Sydney, there are few good career opportunities. But it certainly has it's charms and the tipping point for new arrivals is about 2 years. Give yourself more time.
Keep busy! Do some volunteer work as it will be a way to get some work experience and meet like-minded people, if you don't have PR yet (most jobs require PR). Join a gym. Find a cafe and bring a book ... just get out of the house. Search the net and you'll find countless stories of people who have experienced loneliness when moving to a new country. Try to find an activity that you did back in Alberta and replicate it here. Even better, find yourself a Canadian expat and let her/him be your mentor. Chin up!