What do I do as a mother whose child was basically kidnapped from me by his father?

I'm a young mother and I'm going through an unbearably rough custody case. My son's father and I were engaged, then I found out he was cheating on me with his manager at work. We then had a mutual agreement to part ways. I moved in with my parents for a duration of time and we compromised, had a verbal agreement to share custody equally, meaning we switched off every other week. Randomly one day my son's father refused to return my 6 month old son. My son is currently 11 months old now and turns a year January 22nd and being that he signed the Acknowledgement of paternity we had equal rights and there was nothing I could do. He refused to let me see my son for 4 months, even went as far as attempting to alienate me from my son and teach him to call his new girlfriend mama. I'm representing myself, so what should I bring up in court and to the judge? Also, If my son's father filed a petition and temporary custody order before me but failed to serve me. I filed a counter petition asking for temporary custody. Also could I still get temporary custody even though I filed after him? I was waiting for the judge to sign my papers, so the filing took longer than planned. My court date is supposed to be January 15th if I serve him within the proper time span and his was rescheduled for January 22nd. Is there any way possible I could acquire temporary custody even though it's his hearing? How will it look on him in court if he filed an affidavit of indigence and his current girlfriend is pregnant? Which makes 3 children in total. Our son, her son from a previous relationship, and their fetus. If he signed a Pauper's oath, could he get in trouble if he had a job when he filed as indigent?