want info on birth family

My name is Dena Miller and I was born on 3/1/1974 in Mountain Home, Id. My adoptive parents changed my name but I was told my name was Angelique Marie at birth. I was adopted at the age of 4 months and the records are sealed. I don't know if this will do me any good but I am hoping someone has information that I cannot access without paying the state of Idaho and a lawyer to get. I was told my birth father did not sign the adoption paperwork and was probably not on my original birth certificate. If anyone can help me, please respond. Thank you.