How do I catch up my son's child support

by Joanna
(Philippines)

I'm Filipino who has had a child with an American citizen. My son is five years old and his father acknowledged his birth certificate and he was registered in the US before he was registered here in the Philippines. I have not heard much from his father since and I am wondering if I can still get child support as I have been going through some health issues and finding it difficult to keep a job since I am unfit to do so.
Also, will I be able to get back all those years in which he has missed out on his child support payments?