OP, you sound a lot like me. I'm a biological male who identifies as bigender/genderqueer currently, but my feelings on my gender are always changing depending on how I feel. Do you ever have the urge to crossdress or paint your nails, shave you legs, etc.? Usually, when I'm more aroused, I feel more feminine, sometimes to the point where I seriously question if I'm a lesbian in a man's body and if I should get hormones or even SRS. But sometimes I just feel agender and my gender expression doesn't matter too much, if at all, to me. And then there are even times when I feel aggressive and power-hungry take on a dominant role, but strangely when that happens I don't feel any need to make my body more masculine. So, on average, I'd say I'm bigender.
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"I was a victim of accidents, as are we all" -Kurt Vonnegut
"The surest way to corrupt a youth is to instruct him to hold in higher esteem those who think differently"-Friedrich Nietzsche