Scared too lose my son through court

My situation is pretty messed up. When I was with the father of my son we had a talk about if we were going to have a baby what will he do and he has said that he would be there for me and everything, weeks later i found out I was pregnant so i tired calling him no answer and txting n he didnt answer me for days so i can tell him in person but he lives 3 hrs away . long story short with that i had to txt him it and he had said it wasnt his and denying so through the hole pregnancy my parents were there for me and at birth when my son was 3 months he got a hold of me so I gave him another chance we can talk for couple months and see if his attiude n ways has changed well he screwed up 2 days later so then i gave him another chance (me being stupid and feel bad) then he screw that up ( really bad)) so his mother said he wants to be in his life when i was prego we talked but then she started ignoring me ( and shes not that kind of person) but then he had told me that its because he told his mom it isnt his because he was mad at me.. My son now is 18 months old next week and i havnt had nothing to do with him or his family and then i get a txt from his GF saying why does he have my number in his phone and to never talk to him again then he txts me from his phone calling me a B***h and a Hoe so i said stop txting me then n hr later there like we wanna come see him I sayss NOOO stop harassing me! so i ignored all there txt msgs n I called rogers and changed my phone number cuz i had the old one for a long long time so now he cant get a hole of me But the only reason there txting me cuz she had told me that she told him to step up .. everyone is telling me to relax they cant do anything because he hasnt been with me sence the day i found out never meet him once has 1 baby picture i sent to his mother the day i came home he is not on the birth cirtificate and my son has my last name.. Im scared that he will listen to this girl and try to take me to court for custody or even supervised visitation but i want them out of life he was never in his life or mine and he doesnt even know where i live. Can he take me to court and will i lose my son?? i cant even leave my son for a short amount atime without missing him so much ( im still going through postportum depression just a bit tho) cuz i have depression on top of that and my biggest fear is losing my baby.