Being paid under minimum wage and believe I'm a sham contractor

Okay so from the start. I have been self employed since around covid took off. A few incidents happened and then I couldn't drive, received a few conditions and have lost half my hearing, completely deaf in one ear.

I get called for possible ongoing work by someone who owns and sorta runs his family business and told it's for just a few hours up to 3 days a week and will be paid not a bad amount for something that would always be guaranteed. So I didn't mind it too much. However, this was not the case and was 4, sometimes 5 days on occasionally Saturdays required to keep up with the workload.

When the minimum wage amount was announced to go up, I thought shit, I'm just going to about above minimum wage so I asked for a higher hourly rate and I got it. This was the first time it had gone up in the couple years I had been there for at the time. I recently asked for another and I was insulted by what was offered, which was based on advise from someone else. I said that I read on a website the average hourly rate is a bit higher than that, but was one of those sites that offer a free check or 2 then you have to pay. I was told to get the information and we'll talk about it later. I'll mention details at the end.

Possibly sham because I'm paid an hourly rate that was pitched by them, they own all their machinery and equipment as well as provide the materials used to make their products and has to be done there on site. Some days I don't have a break due to too much work and also needing every cent I can get as I don't get paid for any breaks, not even 10 minutes. I have been told multiple times that I need to have a break so it looks good in my time book (not invoice book owned by me, but a time book they supplied and hold onto). I can't take on other jobs/work as I have too much to do for this place. They make the decision on what my pay will be and wouldn't even accept the average, let alone what I would charge if they were a customer to me instead of acting like my employer. I pay my taxes and super. Is this why businesses look to do sham contracts so they don't have to pay these?

Now I was under the impression that minimum wage was just in general and when I looked at all the information I needed, I realised that minimum wage is for permanent staff, therefore casual rates need to be added as well to make up for all the benefits and leave that casual don't get. So now I know that, I'm looking to get back paid what I'm owed, but if they try to say nope not employed by them instead contracted, how am I suppose to price otherwise? I mean when I get paid into my bank account, theu description includes the word salary. That could possibly work in favour for me I guess?

The real question is, can I fight it or just give up and proceed back to normality in an actual job position?