Im 18 and my mother won’t let me help her

So my mother has various illnesses and one is diabetes. So this morning I tried to make her an egg sandwich and instead of using the bottled sunflower oil I used the spray of olive oil in the pan and started cooking the egg.

Anyways half way through she got really annoyed and lost patience because it wasn’t “cooking” and then just chucked it in the bin and said how she’s been doing it HER way for a lot longer and how my way wasn’t good and how I’m exactly like my dad blah blah

I also want to note that Another time I went to the shop and bought some low calorie / less fat bag of cheese and she flipped out and refused to eat it even though there’s hardly a fking difference...

I don’t understand why she can’t just cut back on certain stuff and if it starts with a fking spray oil she should be willing to atleast use that as a small change. I cant cope anymore with how her foods come out drenched in oils and this is why I started feeding myself when I was 15 because she has no sense of cutting back and portion control.

I also want to mention that my brothers are both most likely morbidly obese at 25, and 17 just because she feeds them absolute shit! And there too far gone to see it and help themselves.

I’m just ranting right now but honestly if I carried on letting her cook and decide what I eat then I would have probably ate myself to death right now but I’m just so mad because my family don’t want to make even the slightest of changes to help their health and both my brothers are gonna end up down the same route as mum include being diabetics and then I’ll have to look after all of them.

Not to mention aswell that my eldest brother LIVES off takeaways and whenever he orders he gets my mum a pizza and feeds her loads of shit

This might be pathetic but more than just over some oil and cheese it’s don’t want to sit here and wait till she dies from her unhealthy ways. I’m fking tired of this family and I can’t wait till I can save up and move out and properly look after my self.