Welcome to the forum. It is good to see you reaching out for some support. Your question is a common one in determining which type of health professional you need. There is a page on the Beyond Blue website that outlines the difference between the difference professional groups. https://www.beyondblue.org.au/get-support/who-can-assist
There are a few other variables to consider such as the availability of psychologists versus counsellors where you live. Another consideration is the level of treatment that you require. This would be best discussed with your GP as Sleepy has pointed out. Another option would be start with a program like Mindspot (www.mindspot.org.au) or NewAccess https://www.beyondblue.org.au/get-support/newaccess
Both of these programs are free and provide treatment by counsellors and you don't require a GP. They complete an initial screening and may suggest to you that you need to see a psychologist based on the first visit or assessment. Both these programs focus on people who are experiencing worry, low mood or life pressures.
NewAccess is only available in some parts of Australia so you would have to do a search to see if it is available in your location. Mindspot is done online with some telephone counselling.
In any case, a conversation with your GP will likely help you determine what level of care that you need and want.
For many people, it is how the practitioner makes you feel and the comfort you have with them. Sometimes this takes a few sessions to determine. It is possible that you might start sessions with a psychologist or a counsellor and it doesn't feel like a good match. If this happens, I encourage people to try someone new until they find the right fit.
As Sleepy has mentioned, it can help to talk and if you feel comfortable, please post again. We are listening.
Wishing you the best possible outcome,