Family being dishonest about money

I'm worried that my foster parents are not being honest about the house finances. We are in a rental share house situation:

Me (I'm 26yo), my 1st younger brother ( he's 23yo), and my 2nd younger brother who is still a minor (17 yo). Our foster parents (but I've always seen them as parents.)

It was my idea to move into a big rental house with plenty of space because the last rental wasn't big enough ad had a lot of maintenance issues.

So we did in May 2019, this place has four bedrooms plus a granny flat separate to the main house, there's a nice pool, big backyard for a suburban home. Plenty of parking space, a huge double garage plus another single car garage. It has all of the amenities you could ask for. Everything seemed great and we all looked like we were moving forward.

Me and my 1st younger brother went halves on the $4250 bond @ $2125 each, even though our foster parents are on the lease too. So they said they would pay us back for their share of the bond. But they haven't as of 02/05/2021.

The rent is $850.00 AUD per week, including water but not including power or internet. Originally I paid $300 per week and my 1st younger paid $300 per week and my foster parents paid $250 per week. We decided to rent out the Granny Flat to a lady for $240.00 per week to bring the costs down. So I now pay $230 per week. Which is better.

So at this point there was x5 rent payers.

I don't know how much the others pay for rent though.

Then there was an extended family drama with our aunt/uncle (a sister to my foster mother + husband which my foster parents felt sorry for. So they allowed them to move into one of the lounges with a spare bed. Which originally I was fine with so long as it was only for a short while until foster aunt/uncle could find their own unit to stay in etc. Things didn't work out that way though and they have stayed until now, paying or not paying a contributory amount towards rent since FEB 2020...

My 1st brother loses his job ( he was a musician on a cruise lines) in March 2020 and had to use his savings for rent for I don't know how long. Not much communication about how many weeks of rent he had enough money for or anything. Plus he could of got AUS citizenship easy as we are of Australian Descent and then got govt help until he got back on his feet but he wasn't proactive about that either.

So there's only four rent payers now, and foster parents not being transparent about bills, rent, and how these are being paid etc, only letting me know when there is an excessive power bill or something, asking for contributions to pay for things like their dogs grooming and trips to KFC lol .
Am I being leeched on by my family?

Is my musician brother who has been out of work too proud to do anything else to earn money? or just depressed?

I have scrubbed dishes until the skin of my hands have cracked open and bleed like paper cuts all over.

I have thrown boxes of frozen fish around with the boys until my arms and belly are well bruised.

I used to push bike for hours just to do half an hour of work at a fish farm to earn some extra dollars.

I have worked up to three jobs at once while studying when I was younger and starting out.

I don't mind helping out every now and then but surely everyone must have a mind to be self sufficient or aim for this status at least. I work a job that isn't ideal, but it pays my bills and such but I can't keep walked over financially like this. My foster parents are pensioners and foster mom is on disability / "disabled", but can drink plenty of alcohol with her sister no problems.

I know everyone has some sort affliction in their lives they need to overcome, I have had multiple heart surgeries and expect myself to fit into society like everyone else, get a job, work out, eat healthy, sleep properly, plan for the future.

I need help as I think people in my life are using emotional connections to control me, manage me, like I'm my foster parents pet, I've been called a pet and a slave jokingly, but was it? They're not honest about money. What if they though they could talk these seemingly dumb foster kids into paying for their retirement instead of working it out for themselves.

When I ask about bills they are very vague in response and move to another topic very smartly.

They have their own adult blood children who make money, drink it, smoke it who don't help work out a plan for their parents.

I would contribute to their retirement only if all of the siblings do this, not just me or a few of us.

It's a very sticky social/financial situation with my family/foster family.

They lied about me being adopted when we were not adopted, because if we were adopted then the government would not have to pay foster parents to raise us. It's a contract. A plain and dry contract.

So if they lied about something as serious as that, then lying about money would be nothing to them.

I always look up to the future instead of looking down on the past.

I need the wisdom to navigate this,

Regards,

Young man trying to navigate life