CSA issues from the Philippines

I would like to ask some advices from you regarding me and my son’s situation. I got pregnant and the guy did not take his responsibility to me and now I was trying to fight for my son’s right to acknowledge him as his son. Can I sue him even if we are not married? I also went to Public Attorney’s Office to file a case against him but I have done nothing because of lack of proof. And I was hoping that DNA test would be the better proof, sadly it is very expensive to process and I he wont give me sample of his specimen.

What should I do? My son is only 6 months old and I had already take hard some insults words from the family of the man. They are influenced family and I heard that the guy will getting married from other girl. Child Support Case only I was trying to fight. For my son I will do anything for him.

I am here in Cotabato Philippines and I am Maricel Cuevas, 26 years old; Part time cashier in Net Café, I earned 60 pesos a day and it is not enough to raise my son with this daily income. On the meantime, my son is sick. I hope you can help me. Thank you so much.