Well:
Try going out with a girl? This can be fun, because it doesn't have to be sexual. Try finding a girl who could be attractive, and trick them into thinking you are trying to build a friendship. See if you get attracted to them? Frankly I Think this would be easier than actively trying to pursue all out lesbians. It can even be a straight friend -- it doesn't matter. I'm going to hell...
I'm aware of a couple of people that are pretty much non-sexual. Have you ever been attracted to anything reasonable (Johnny Depp excluded)? try looking into different kinds of sexuality, including pan-sexuality, see if any fit?
P.S. if you score with the female friend, record it for me

(I
am going to hell...)
Um I am not sure if I have been attracted to anyone or not I do remember looking at a calendar at school and getting teased for saying this girl was good looking