It saddens me to read some of the replies to this thread. I had such a wonderful relationship with my dad and though he died almost fifty years ago, I still think about him a lot. As great as it was, however, I don't remember him ever telling me he loved me. But I knew he did. It was just something that I knew. I never hesitated to tell him I loved him though. My children, who are all grown now, and I have a wonderful loving relationship. My two girls find it easier to say, "I love you" than my son does and they say it far more often, but he says it too. I don't hesitate for a minute to say "I love you" to them and I tell them often. My mother was very affectionate and that probably accounts for the way I am. My wife was not raised in an affectionate home and she, therefore, found it difficult to show affection. As in the case of me and my dad, our kids just "knew" their mother loved them.
I wish I had sage words of advice to offer. A frank attempt to convey your feelings to your father is certainly worth trying. Some people obviously have great difficulty expressing their feelings to another person related or not.
I think everyone needs to love and be loved. I hope that you are able to find a way to give itm and to receive it from your dad.