You youngsters, Coatl and Paulina, IMO you've got to go for it!
Whichever way one looks at it, wishing to be a girl isn't "normal" male behaviour so if you do have those feelings, then it surely isn't a whim and indicates there's "something wrong"
The first step is always a gender-therapist wherever you are and they certainly aren't going to steer you wrong and encourage feelings that you don't already have.
I suppressed, denied and put-off until finally I literally cracked up with a nervous breakdown at the age of 54. Whilst I'm very happy indeed now to be living in role and on HRT, some days it is all I can do to keep myself from slipping into negativity and despair from the regret of all those lost years. I wouldn't wish that on anyone.
regarding coming out to parents etc -
As I said on another forum to another young person in a similar position to yourself, perhaps you could manage to go and see a gender-specialist first, discreetly and on your own?
- that way, when you do open up to your parents, you are saying "For years I've been secretly tortured by the feeling that I am actually a girl
and I've now been to see a professional who specialises in the field and they think that I am in fact transgendered....." That approach might help to add some credibility and cut short that stage of "my child has this strange delusion"
In my own case, I had already told my parent's first, but there is no doubt that their attitude changed for the better as soon as I returned from the first official assessment. They were and are still struggling to come to terms with things, but from then on they knew and had to accept that this was a real and valid situation that they needed to adjust to.
If I had the chance to do it over again, I would do it that way round - I'd be interested to hear what other people think of that idea?