I need closure?

My father ped away three years ago. The first time i ever met him was at his funeral. I looked for him for 13yrs then i received a call that he had ped on. I found out that the town i grew up in was the same town his parents lived in and they saw me plenty of times in public but never said anything. I was conceived out of wedlock so his parents and him disowned me. At the funeral i met my younger sister and a lot of cousins and finally my grandmother. The only thing she could say to me was that i didnt know you existed so we didnt put you in the obituary. Since the funeral a couple of my cousins tried to contact me but i felt so enraged that everyone knew about me and didnt try to contact me so i cut them off. Should i try to have a relationship with the other side of the family. Its hard enough not to be able to say goodbye to him.