Need to vent/advice

I posted this on general pregnancy last night but deleted it and feel better posting in this group. I need to vent. I am lost. I’m 15 weeks pregnant and I met the father of my baby 2 years ago from someone who I thought was a close friend. Let me give a background for everyone; Him and I started hanging out and talking (I didn’t know they ever talked) until she started getting extremely jealous and would post about me on social media.. she was with his best friend prior to this. Well this went on for awhile before I caught on and once I confronted her she said it didn’t bug her but it did. We all were friends (weird I know) and I was admitted into the hospital and was in ICU for three days in an induced coma. I woke up and once I got better I was still in the hospital because I got pneumonia I got a call from him that he had sex with her. I was devastated. I decided from then on out I would cut them both out of my life because they were no good. It was hard because I worked with her and eventually we became on good terms once she found out she was pregnant. She had slept with him, his best friend, and other guys so she didn’t know who’s the baby was but the bestfriend stepped up and wanted to be with her. They were together and the guy and I hadn’t talked for a year and we finally did. Her baby was born and I’d here from him every now and then.. I had a soft spot for him and I think i don’t know why. He treated me like shit and was emotionally and verbally abusive towards me.. I should of stayed away along time ago. Fast forward to today.. I am 15 weeks pregnant like I said up there and he’s the dad. Things have been rough trying to figure out everything and he swore he’d be here and he loved me and wanted this family but now all of a sudden the girl is getting a DNA test because she believes her son is his child too. He became distant with me and blamed it on my ex but come to find out he’s asking to meet with her and her son and completely abandoned me. She told him she wishes I was dead and my baby also. She was the first person I told when I was pregnant and has been saying she’s here for me which is clearly not true. Why now get a dna test and break up with her boyfriend? I know it’s my fault for ever messing with him again after I got out of the hospital but I didn’t want an abortion. Things are so fucked up I just feel alone and I wish I knew what the right thing to do was. He blames him leaving and being distant with me on my ex because I had pictures of us on social media still but come on... his child growing inside of me is so much bigger than anything especially my ex boyfriend. I hate feeling like I need him because I know I don’t.