Finding Who You Are!!

I am new to this, so here goes! I am 43 years old and I am trying to find closure to this. According to my mother she never signed any papers to have me adopted. Unfortunately, my "so called father" I call him that because I have never met him but met his sisters who I thought were my aunts, are telling me that he never knew I was his etc..its alot of he said she said things. Obviously no one is going to tell me the truth but I need closure for myself regarding if I was legally adopted or was i just given away. and If that is the case then how could i be added to medical insurance by the family that raised me; I mean I have so many unanswered questions. I just want some type of help!! can someone guide me in the right direction. And not to mention I have chosen Family as my topic for my "multigenre research paper for school. So this is my own personal journey.