Hello Michelle and welcome to the forum.
There are a lot of tips and tools on the home page http://www.weightloss.com.au
which I have found to be down to earth so be sure to check that out.
I feel you goal is realistic in that time frame but that all depends on you and how focused you are. Sometimes just cleaning up your diet and adding exercise will get you there. By 'cleaning' up I mean limiting you fat intake...not from good sources, nuts, fish, avocadoes etc but from high fatty foods, fried stuff and chocolate, biscuits etc. Make these things treats not the norm. Be aware of your snacking and more importantly your portion size.
Portion size may also be a key factor for your carbs. When having bread or cereal check the serving size and don't go over that per meal. Cereal is a classic example, everyone says eat more cereal but most serving sizes are 30-45 grams depending on how 'heavy' the cereal is. Yet many people would fill a bowl so may well be eating 2+ serving sizes. It's these sorts of things that run you into trouble.
Good luck with your weight loss journey.