Your situation is too involved for an online answer.
Using the written documentation you have is a good place to begin. Contact a local lawyer - many may give you a short free consultation - to discuss your specifics. Far too many variables exist in the short post you wrote for any further observation by me. Many attorneys have information posted here on Avvo.
You might find my Legal Guide helpful "How to Choose A Lawyer For You"
You might find my Legal Guide helpful " What Do I Tell My Lawyer"
No one can know what the record is in the case because online we cannot see your documents. You need a lawyer. Check with a lawyer in your locale to discuss more of the details.
Good luck to you.
NOTE: This observation is made available by the out-of-state lawyer for educational purposes only. This observation is not like a communication with a lawyer with whom you have an attorney-client relationship along with all the privileges that relationship provides.
Contact an attorney to seek modification of child custody. The age of the child also may impact the success of the modification. If there are concerns of abuse of the minor child, contact the Department of Family and Child Services.
I would strongly suggest you file a Petition for Modification of Custody as soon as possible. You can also request that the Court appoint a Guardian Ad Litem to look after the best interests of the child. In order to be successful in your Petition, you will need to show the Court that there has been a substantial change in circumstances since the last order granting the father primary physical custody.
This situation is too important to ignore, and you need to contact an attorney as soon as possible to learn about your best options and the steps / costs involved.
If you would like to discuss things further in a private and confidential consultation at no cost to you please do not hesitate to contact my office.
Please know that this is a general interest posting and does not create an attorney-client relationship.