You story makes me reminds me of my girlfriend. Her family is
exactly like yours. 
Allow me to share with you some of my
experience for you to hear.
"She call me rebellious
when I said i wanna go over to my bestfriend's place for a
sleepover".
Every parent love their children. The 9 month of gestation is
not there for no reason. She loves you, but she doesn't know how to
express it in the right way. She's angry that you're going for a
sleepover at your friend's place because she worries for your
safety because she cares about you. 
Instead of expressing her love for you in
the right way, she scolded you 'rebellious' in a moment of
anger. I'm sure after that fight, both your mother and you felt
hurt.
I respect my mom, i love her,
i took care of her when she's sick, i bought things for her with my
pocket money when it's mother's day or her
birthday.
You're a sensible girl because you took care of her well when
she was sick. You even bought her present when it's her birthday.
You are a good daughter, and you're a good girl.
She took it out on me when
she's in a bad mood. She insults me. She hits me. She said things
that a mother wouldn't say. She controls everything. She call me
rebellious when i gave her attitude when she accuses me for doing
something i didnt do.
I must admit that channel such negative emotional energies to
children is not the right way of stress management. When it comes
to this, I'm very used to such cases because my girlfriend would
come and sought comfort in my everytime when her mum scolds or hit
her. I can tell that your mum is very controlling of your life and
you rarely gets your freedom. As I've mentioned previously, when
she called you 'rebellious' she was angry at that moment in time.
There are much more better ways of communicating other
than causing so much negative emotions.
And i wanted to work for a
year to save money for private diploma. I dont wanna take that huge
sums from my mother. I wanted to rest for school/work for a week or
two first.
You are quite self-reliant which is a good thing. It allows you
to have the ability to survive in this tough environment. Seems like you already have a plan in your
mind, why not share it with us or your mum? Let her know what is
your plan and convince her that you are confident about
your education/life plan.
When I told my mum I wanna
quit polytechnic and wanted to focus on my business, it
took me just 15minutes to convince her my idea and gained her
support. It was like a business meeting with my mum. It's an
Art to convince somebody and listen to your plan. I believe all you
need is just some quality time between you and your mum,
and talk to her about your plan.
Hell yes, she's worried about you and your life. That explains
why she assert so much control over your life. 
I can show you the ways to help you
change this life and help improve the relationship between you and
your mother and brother.
I recognise your effort in trying to be a good daughter. From a
3rd person point of view, it's a matter of
communication. In order to communicate
effectively, you need practice and know the right skills.
