Who has custody?

My child's father and I share custody, however he is the primary custodial parent, however he moved to New York in 2007. I assumed that I had become the custodial parent. The child has continued to live with the Grandparents who are now trying to establish custodial rights. I am not in favor of this. I have allowed the child to stay with the grandparents for the sake of the child and for educational purposes. I have provided for more than 50% of her care without any financial support from the father since his departure. I have paid all the out-of-pocket expenses for the child. I was never ordered to pay child support. I have provided both medical and life insurance for the child since the Court order. A responsibililty the Court ordered the father to provide. What should I do? - Is this your question? Add additional information