There's nothing wrong with being asexual. Often times it's just a phase, but it comes down to more of you accepting who you are. Just because your dad doesn't agree with it means that something is wrong with you you're still the same person. I remember once when my ex girlfriend broke up with me a few years ago I completely lost interest in men and women, even though it only lasted for a few months. But like I said, there is nothing wrong with you