Lack of Effort

My father and mother married when they were young and divorced when I was about 6mos old.  From then till i was about 16, my father and mom split custody of me.  My mom had me 98% of the time and my dad the other 2.  I saw him maybe 3-4times a year for a couple of days each time.  The rest of the time I never saw him. He never came to any of my concerts, plays or sporting events.  He never drove up just to see me, he would never call me on the phone just to talk to me, or write letters just to see how I was.  The only time when i would see him would be when he came to get me.  And when I did go to see him, I was scared.  he was like a complete stranger to me.  his parents, my grandparents, are great people and I love them.  But I feel like my father never wanted me, and never really loved me.  I feel like he was playing the part of a father.  He never really was one.