Gender identity and fluidity?

For those who don't know- there is something called gender fluidity where people are go back and forth between masculinity and femininity over either a long period of time or from day to day. I tend to fall into this category as in some days I really feel like I should have been born a boy rather than a girl. These days I hate the fact that I have breasts and wish that I could undergo surgery to have a more masculine looking body. Other days I feel like I am in the correct body and all is well and good.

My question is there anyone else that has this fluidity and how do you deal with the days/times that you fell more like the opposite gender? How do you conform your body enough to match how you feel without going through the obvious extremes of surgery and hormones as it will eventually swing back to your biological gender?