So I Just Found This Out What Are Your Opinions

I was born and raised in hamburg new york and my parents split up when i was 2 years old and have since been remarried. I lived with my mother until 4th grade then i moved to my fathers until i was kicked out when i was a junior in high school. All throughout my life my grandparents have basically raised me i was always over there and had such a strong bond with my grandfather even tho i lived with my father he always found ways to spend time with me and take me places and do things with me and what not. Well this is where the story gets alil twisted. My grandfather dies in 2001 while climbing a mountain in south america. I was the first to find out and had to tell my grand mother. It was the worst day of my life not only did i have to witness here having a heart attack and being rushed to the hospital right infront of me at the age of 13 but i felt like a big part of me died inside as well. My grandfather was my idol and the most important person in my life. Right after that happend my mother moved to georgia. Basically running away because she didnt want to "deal with my grandmother" Well my father got a tip from someone saying that i might not be his son. So I was lied to by my father and tested for paternity. he told me i was being tested for cancer because it runs in the family. When he found out i wasnt his my life completly changed. He started acting wierd and treating me worse than he already did. For all i knew the last 17 years of my life he was my father. i just found this all out about a year ago and i am 21 now. because my aunt was drunk and told me that he wasnt my father. like everyone knew except me. Now my mother knows who my father is and refuses to tell me. and its really been bothering me. I dont know how to explain what im trying to say but i believe my grandfather was my biological father and that my mother doesnt want to reveal that to me because she is afraid or embarrased. like how could her father be my father right? well heres another twist. my mother and my aunt where both adopted because my grandfather "couldnt have kids" But im thinking it was the other way around i think my grandmother was the one who couldnt bare children. so yes he was her non biological father but could be my biological father at the same time and technically wouldnt be incest would it? Im just thinking that something happend between him and my mother and she is afraid to admit it because she is disgusted or embarrased. when my grandfather was alive him and my mother did have a rocky relationship. Not something i would call normal. I dont know how to explain that as well But when i confronted my aunt about it she acted really wierd like yes thats whats happend however im not the one to tell you. I could just sense that was what she was thinking. And also I believe my grandmother knows this as well. But doesnt want to admit it. The reason why im thinking this? is that honestly more than half the people that know my family always commented on how i look just like my grandfather and have alot of his traits in every aspect. and the more i look at all his old pictures and pictures of me i can see the resemblence and its very very strong and it kind of scares me how i resemble him. Not in a bad way but a way that makes me really want to findout the truth and it really bothers me that my mother will never ever tell me who my biological father is and its been eating at me ever since i found that out. Does anyone have any thoughts on this?? I know that i wrote a book here but im sorry I am just venting how i feel and if i dont use proper grammar and punctuation i apologize