It is not kidnapping; especially if you obtain a restraining order against this person for you and your child. You are moving so I would ensure you begin the process of divorce by consulting with an attorney in the state in which you will be living to see if a) which would provide a better option for you in terms of support payments and separation of assets and debts in general and b) if the better position is in the new state, how long you need to be living there to establish residency.