I don't know how to tell my family what I want to do!!!?

I have been in the same situation for the past two years now, all I can say is that you should keep it to yourself until the time is right. Resist the temptations and wait. If the time never comes, then so be it. I only rejected to do the creed of Christianity in church and it caused massive problems, my parents were devastated and my mother is still sad, my father is still angry to this day about it (it's been 2 years).

Also, becoming an atheist/agnostic is not just a quick choice, it can take months, even years. It took about eight years for me. A lot of theists claims to have been a non-believer for a while, and some cases might be true, but most of them just went through a phase, so IF you decide to tell anybody, first make sure of what you stand for

You have to remember that it's your personal choice, and nothing they say should come in the way of that.

If your brother thinks it's stupid to be a vegetarian, maybe show him a few articles that show the benefits of being vegetarian. Also, your mother cannot stop you from believing or not believing in god. That being said, church isn't always horrible, even if you're not religious. You get to meet new people, learn new skills, and go to fun events. Maybe you could consider church as a social event rather than a religious event? If you really don't like church, you're going to have to talk to your mom and tell her straight up how you feel. If she reacts badly, unfortunately, you may have to keep going until you're old enough to be able to disobey her.

Well, it isn't stupidity, but it is not a proper diet. It is not how we are designed to live. Most people who become vegetarians have been duped by others to the horror and pain of animal killing and such. but for you to live, something must die--be it plant matter or animal. God set this up for you to be able to understand the spiritual realm where in order to live after you have sinned, something must die. You choose, but if you choose vegetarianism, then don't put down those who have their own opinions or you can't have yours.

Why do you have to want to in order to go...there is a sorta depravity and selfishness there that everybody over 21 sees immediately.

Your mom didn't want birth pains, expense, staying up at night, cooking, cleaning, having no fun and a billion other things but she didn't say 'screw you' and "why doesn't he do what I want "

I know vegans who choose this because meat is not efficient (not to mention sentient), it's just too high up the food chain. The pound of meat in the pot costs a lot in feed (grass, grain etc.. and water), which would be better spent on crops that would be consumed directly. Ref: Diet for a small planet.

Tell your mother that she can try all of the physical force she wants, but it will do nothing to your mind, thus she will have to rethink her tactics and possibly use subtler, less annoying methods