Feeling lost and confused, am I alone?

My Great Great Grandma, and my Great Grandma are Sioux, the problem being, my Great Great grandma was adopted, so the only information of her, is that she is Sioux, but have no way to contact her family. The only thing I have is that her and her daughter [my great grandmother] are listed as Native American on their birth certificates and are Sioux.

That makes my Grandmother 1/2, my mother 1/4 and me 1/8ish.

However I have had 0 luck in tracing too much information, but I feel this as a huge part of me.

Will I ever have any luck?

Or will I be doomed to search forever.

…. I feel so lost. This identity crisis is driving me up the wall…