Many drug and alcohol services have counselling available. You should call your Local Health District Intake Line, on this website under Drug Treatment. Or have a look at the websites on this page for services who do phone counselling and/or provide lists of face to face, phone and web counselling services available. ADIS does over the phone counselling with skilled professionals and also has a comprehensive database of services who offer counselling. Call them on 02 9361 8000. There are many psychologists listed on the web or in the yellow pages.
In order to practice, a psychologist should have a university qualification. Ask them about their experience. They should also be a member of a professional association such as the Australian Psychological Society. You can look at the Society's website for their advice on what qualifications a psychologist should have. https://www.psychology.org.au/community/specialist/clinical/
Word of mouth is often the best recommendation, so it can be useful to use your peer network and ask your friends who see a counsellor if they are happy with them.
Psychologists attached to public clinics and public hospitals are free but you may have to wait for an appointment. Private psychologists are not cheap and may charge somewhere between $100 and $250 for an hour. Your doctor can do a Mental Health Plan that will allow you to get up to $80 back per session for up to 10 sessions.
It can be very useful to think about what you want to get out of your relationship with a counsellor before you see them. Write a few things down. On your first appointment, it may help to let them know what you are wanting to get out of the sessions and to remind them of that from time to time if you feel you are not getting the most out of your time with them. If you do not connect with them, try another one, and keep trying until you find one that you click with and is able to help you meet your goals. Some psychologists insist that you cannot treat any issues you may have until you stop using drugs, however this is increasingly considered unhelpful, judgemental and plain old-fashioned. People who use drugs are very capable of working through our issues, of knowing what we want and of reaching our goals. There are some excellent counsellors out there and some people find them very helpful for working through various issues such as grief, violence, anxiety, depression and childhood trauma. Some counsellors are very skilled can help you find ways to change the way you use drugs if this is your goal.