How do i move on after this?

what should i do..im so confused. i was with my ex partner for a year and then i got pregnant, we talked about having a baby but it did come as a bit of a suprise, anyway i was due to go on holiday, which he was very unhappy about its the same place i go every year and had already booked it so i went, he was fine on the day i went but when i go back he was distant with me and we didnt see eachother for a while, anyway we started talking again and he told me to add him on facebook, which i did anyway out of curiousity i went back in time on hes facebook and noticed some messages between him and another woman, there was clear flirting there, i wasnt too upset it was more due to the fact he had such a go at me for going on holiday when he was doing that, so i didnt feel he had a right anyway i deleted him from facebook and we contined not to see eachother a few months later he asked what had happened and why i stopped talking to him, and i explained about the message on facebook. he went wild saying i was lying and there was no message there and i made it up. i told him the date it was sent and told him to go back and look on it, he said he did and there was noting there, i said add me on facebook then and ill show you it, so he did, i went back and as sure as hell it was gone, we argued about it and i said, dont make me message the woman to ask her, he said go on then, so i did, she said 'i dont remember but if your saying its there it must of been' i told him this and he then came back and said the woman had said i was a liar and i was crazy, so i messaged her telling her a few truths about him as i believe there was something going on, so i tryed to warn her by telling her he had been to prison for beating up hes ex so she doesnt let him see hes son anymore, anyway this angered him and he text me saying the only person he wanted to have hes child was hes ex who he loves and because of me being pregnant she never wants to see him again and i ruined hes life. he told the woman stuff about me on facebook, i didnt know what i just knew what she came back and told me, saying that he had called me a whore ect. after this we didnt talk until i was 9 months pregnant because he said he didnt mean the text he just wanted to hurt me, he came round and we contined to argue about the situation he got agressive and started pulling my hair saying he wasnt flirting with her, i said i didnt believe him it got heated and he left, forgetting hes phone. i then went through it, i had to see what he had said to her. he said he was still in love with the mother to hes other child, he told her things that he had never even told me about the situation and said because of a lying whore like me he wont get to see the love of hes life again because he told her i was pregnant, and he wishes i had an abortion because im a slut!.....he came back for hes phone and i threw it at him and shut the door, he was then screaming through my door saying he loved me and i shouldnt believe the messages, but then he wasnt saying it just to hurt me because he obviously never wanted me to see the messages. what should i do? i feel so lost and depressed, hes destroyed my life, how do i get over this??