I hate to say this, but if you are in puberty, there is a ticking clock over your head. Every day that goes by, your body is getting masculinized. Here's what happens if you block puberty (yes, you can stop it in its tracks with blockers and then have the other puberty with estrogen):
http://images.google.com/images?hl=en&source=imghp&biw=1680&bih=804&q=kim+petras&gbv=2&aq=f&aqi=&aql=&oq=&gs_rfai= That's Kim Petras. She got on blockers and hormones at 12 and had surgery at 16 -- the youngest ever. But even if you don't start as young as her, you can turn out great.
I know how terrified you are of people finding out. The horror of how people will react. The desperate hope that you'll get over it (answer: that doesn't happen). Don't believe that I understand? Here's my story:
http://www.dailykos.com/story/2010/8/20/894744/-As-A-Fourth-Grader,-I-Prayed-For-A-Tumor Sound more than a little familiar? I tried to hide it inside me. And kept it inside until 19 before I finally broke down. And that was so, SO stupid of me. I lost my chance to live my teenage years as a girl and suffered huge irreversible damage to my body, and for what? I *still* had to go through coming out to everyone, except by then, I had even more people I had to come out to. It doesn't get any easier with time. If you manage to hold off until your 30s or 40s before breaking down, like some of my friends did, then you break up marriages, lose children, lose jobs, etc.
You write "i don't want a sex change because I know it will ruin my life". That is EXACTLY what I was terrified of. That if ANYONE ever knew how I felt, I'd be rejected by everyone I cared about and live as an unloved freak for the rest of my life. That terror caused me to do nothing in panic while my body was destroyed. And it wasn't even remotely true. My mother's first reaction? "Honey, why didn't you tell me sooner?!" She felt so bad I had been suffering and she hadn't been able to support me. My father took it harder; it took him about a year to come to accept it. But he gave me away at my wedding, and today goes to national LGBT rights dinners, and made his company one of the most LGBT-friendly in the industry. We've never been closer. I've been successful in business and basically living the American dream.... *as myself*. In a body that makes me *smile* every time I see myself in the mirror. Of all my friends, I only lost one in coming out, and that was only temporary. I never ever would have guessed that.
It's so, so hard to come out. But it's not going to get easier. You're just going to suffer until your depression *forces* you out in *much* worse circumstances.
Above all, you need to stop your puberty. I mean, I can't stress this enough. You don't want to keep becoming masculinized, do you? A therapist can get you hormone blockers. You can even get them online, although it's tricky. But whatever you do, please, don't make yourself go through irreversible changes. You'll suffer just like I did and live with the regret that you didn't do anything sooner.
Please... if there's anything I can do to help you, email me. That's why I'm here. I've gone through it all before.