Rabbi Menachem M. Schneerson
770 Eastern Parkway
By the Grace of G-d
22nd of Av, 5745
Chabad of Northern California
2340 Piedmont Ave.
Berkeley, Ca. 94704
Greeting and Blessing:
This is to acknowledge receipt of your letter of the 7th of Av.
There are surely no need to point out to you at length that one of the basics of our Torah, Toras Chaim, is that HaShem is the Creator and Master of the Universe, whose benevolent Providence extends to each and everyone individually, and the He is the Essense of Goodness, and it is in the nature of the Good to do good, particularly in regard to our Jewish people, to whom he has given His Torah, Toras Chaim, of which it is stated that it is "our life and the length of our days", together with its Mitzvoth whereby Jews live.
As you know, and indicate also in your letter, there are Mitzvoth which apply to Jewish males, and those that apply to Jewish females, and the distinction in regard to the fulfillment of the Mitzvoth, is a far-reaching one.
In the light of the above, it is not clear why you should want to interfere with HaShem's blessing and contemplate a change of sex; especially as it would immediately bring in complications regarding Torah and Mitzvoth, even assuming that there would be no problem in other areas. And since this is quite plain and understandable, there is no need to elaborate on it.
As for your writing that you have sometimes had the desire to have been born a female, etc. - it is not surprising that a human being cannot understand the ways of HaShem, Who surely knows what is best for every individual. However, if this desire is somewhat troublesone to you, it would be advisable that you should talk things over with a Torah-observant psychologist.
I suggest that you should have your Tefillin checked to make sure they are Kosher.
With blessing, M. Schneerson