Unfortunately, Old Testament texts would support having you stoned to death and sent into hell with the Sodomites.
You can reconcile the conflicts within yourself, and it appears as if you have done it successfully.
Your brother does not know how you feel, nor can he. In his experience, you are voluntarily making a really stupid choice in life. In your mind, it is not at all stupid; it is compelling, not voluntary. He may remain unconvinced, which is not all out of normal. In this particular regard, I suspect his "Christianity" is not the source of his feelings and beliefs, but serves only as a vehicle to express them. He is afraid of any non-conformity.
Appealing to his reason, you might wish to point out that you are not making this choice for rational reasons; would any normal rational man want to give up all the advantages of living in a male dominant world? Obviously not (to his way of thinking). So therefore you must be being compelled by some outside force to act as you are doing. It may be the will of God that you live as you feel, or something else, but whatever it is, it feels so compelling that you have to do it.
If this does not lead to a brotherly reconciliation, or at least a loving readjustment, challenge him to find a New Testament verse that would justify his attitude of shunning you -- Unless you were raised as Mennonites in which case he will have it handy.
From what I have seen with other similar circumstances, your de facto expulsion from the family does not last forever. It can be years, but reconciliation almost always happens.
Just in the little community where I live for the moment, one neighbor just reconciled with a brother he had not seen in 40 years, and who lives a continent away. Another reconciled with his son after 10 years, said son having spent that time in prison for drug dealing. And another mother coming out of a deep depression when her son was sent upstate under a life sentence for murder; she went to visit him for the first time since the trial and his expulsion from the family circle.
For families, fear often gets in the way of resolution. Never be afraid to make the first motion towards and eventual reconciliation -- the other person may just be waiting for that to happen.
