I’m a female & I wanted to be a boy my whole life. As far as I can remember i used to wear my brothers pants and shirts since i was 4. I’ve always seen myself as a guy. I’ve read and heard that transgender or homosexuality is something you choose for yourself. But how can I choose that at the age of 4? Am I born to go to hell? It’s really depressing me. Will I get punished for being like this? If I become a man through the surgery will allah accept me? I’ve also heard that even though I become a man through that surgery I will still be a female. Is that true? ( sorry for my english)
I surveyed fatawa on this topic in this answer (see also Can transgender people be Muslims, and how do gendered rules and rules about marriage apply?). Basically, there's some fatawa that say it's haram to transition, and other fatawa that say it's permissible under certain strict circumstances, sometimes described as "psychological hermaphroditism".
Countries like Malaysia and the UAE are generally against transgender people. Iran is quite accepting, as long as you're consistent. Most countries are somewhere in between. Individual Muslims also have varying attitudes.
Practically, you're not going to be able to just get bottom surgery and magically everything will be okay:
FtM phalloplasty is expensive, complicated, prolonged, and painful. The surgery hasn't developed to point where the results are particularly natural. Additional surgeries will probably be required, e.g., mastectomy.
One doesn't interact with most people using one's genitals. Even after surgery, most people won't know you've had surgery. However, after prolonged hormone replacement therapy, many female to male transgender people become "passable", meaning that people won't be able to tell you're transgender.
The WPATH Standards of Care (available from http://www.wpath.org) requires a 1-year long "real life test". I.e., before surgery, you're required to live consistently as your identified gender for at least one year.
Most people will spend an extended period of time transitioning (maybe 3+ years) before their body is settled. It's not going to happen overnight. You'll likely need to become accustomed to an "in between" state, and somehow juggle going to mosque, etc., while being in this state.
I can't address whether or not you'll be punished for this.
Before deciding, it would be best to "do your homework" regarding the religious and medical ramifications. Also important is to consider how your family might respond.
In the signs of the last day, one will be women dressing like men or vise versa. It is prohibited for a man to dress like a woman or act like a woman. Or for a woman to dress and/or act like a man. These thoughts come from shaytaan. It is haram to modify your body, unless it is for medical reasons. So things like plastic surgery are haraam. Therefore, being transgender is haram.