I'm not even sure how to describe it...I'll probably jump around trying to explain everything that I can...well...here it goes...

I feel like my parents are always forcing me to do things that I don't want to do. They will always say "I asked you to do it" or "You could always say no." and I feel like if I try to be defiant and say no or refuse that they are just going to look down upon me like I am nothing, that i am useless, they even force me to do things or go to events that I had gotten asked to go to, that I had been asked if I wanted to go or not. I'm the youngest in my family and all my other siblings literally had a 4.0 GPA. I...do not. I'm not the smartest and I have tried studying and it just, it doesn't work with me....my GPA is around 2.9, and my parents are constantly nagging on me to get it up, I try and they still are not satisfied that I am trying my best. They are always comparing me to my older sister who is really smart, deeply religious and an all around perfect child. I tried to live up their expectations and they were always disappointed. The only people who understand me and actually support me are my two friends and my two brothers. They are always there for me no matter what and try their best to cheer me up and to help me to keep going.
I always feel that when ever I get upset really bad that I am so close to just snapping and going insane. I...I just don't know what to do...
I should probably mention that trying to get my mother and I to see eye to eye is just like trying to teach blind people to play rock paper scissors, or mute people how to sing opera. (No offense intended)
so...why do I feel like this? I'm always angry, upset, or ready to snap when ever I am around most of my family.
Today my mother and I were arguing and she said "Life isn't an option." I was so close to saying "So I should commit suicide then?" I've...honestly thought about doing that before....But I realized that my best friends need me and rely on me a lot but...what will happen when they don't? Sometimes I feel like that will be my only option soon is death...
If you took the time to read this and respond...thank you...

I'm sorry you feel this way...But remember that you have people that are supporting you. Feel lucky in that sense.
And don't kill yourself. Even if one day your friends don't rely on you anymore, there's also that big chance that you'll always make new ones.

Thank you HAM, that made me feel a little better, thank you.

I do not know all the details of your situation but I'd say that don't let anyone pull your strings, you want to be your own master, it is your life, not your mothers or your fathers, also you are not your sister, and that should be enough for your parents. If they don't accept you as yourself then there is no reason for you to try to please them. Do not try to be someone who you are not.
Do not do a suicide since it is just an permanent answer to a temporary problem. Try to live your life happily and take joy of everything you can since life is easier that way.
Do not fear what happens in the future since you don't know what it brings with it. Do not feel all blue because of the past since you cant affect it anymore. Live in this moment and take all joy of it since it is the only thing that matters right now.
These are the rules that I live by and I hope they will help you.