I think the points covered above cover what I'd suggest in terms of self teaching, and from a HSC perspective that is only a little in terms of what you need for the VCE. What I'd encourage is for you to speak to a coordinator, a VP, someone "higher" about the issue, and encourage your classmates to do the same. A significant portion of the class raising an issue will be taken seriously - Schools like their cohorts to do well, it is in their best interests to address problems like this, so although it might seem like they won't care, they will! Don't be afraid to speak up, if you are calm and logical in communicating your issues there is no reason for them to ignore them.
Unfortunately, the reality is this. When we are younger we view teachers as these all knowing, all powerful beings. As we get older, we realise that they graduated just like you. They got an ATAR, just like you will, and they went and studied teaching at university. There are no huge barriers preventing "less than competent" people from becoming teachers - It's not like teaching is a 99.95 course requiring an interview and character assessment. They are just people doing their job - And like all positions, some just phone it in, lose the passion, or just aren't good at it. And this can be a day to day thing - Good days and bad. They are human, basically.
I realised this early in Year 3 when I realised I could do sums faster than my teacher. Don't get me wrong, she was an incredible teacher and amazing at her job, but when I figured that out, it was the first time I was like "Oh, hold on." The "aura" that teachers carry disappeared a little. It went away completely in Year 12 when I saw a photo of one of my high school teachers pole dancing (appropriately clothed) - Nothing bad or untoward about it at all, she was just at a club having a dance like many of us do. But that was when it really sank in that like, some of our teachers are only 10 years older than us when we get to Year 11 and 12. They are just doing their job - And while many teachers are incredible (I have a huge respect for teachers), some won't be. Kind of like that person at Maccas who moves really slow and just seems lost all the time, they always forget your sauce, you know the one. It's nothing against them personally - Some people just aren't incredible at the jobs they choose

So, just like you would talk to the Manager about an issue with your Maccas order, you should talk to someone about your teacher! You are at school to learn, and if that isn't being done, they need to fix that!
See, I brought it full circle
