It's so hard when the basic facts surrounding one's very existence are outright lies. I'm almost 52 and also just figuring out who I am. My birth was somewhat of a scandal that resulted in my biological mother's death when I was 3 weeks old. Everything from who my father may or may not be, how she died, how I came to be adopted, even how many siblings I have have been lies, half truths and downright fictional tales. It does such damage to a child, and and adult for that matter, when basic things that people take as given are just not there.
And those that weren't lying, in y case, weren't talking. It got to the point that unless I saw it in documentation from an official source, I didn't believe anything. And now anyone who would have known anything is dead, so there are things I'll never know and I'm just going to have to live with that.