New relationship after narcissist

I was in a 14 year relationship with my ex. I left him 6 months ago. When we first met I fell deeply and madly in love with him. He got me to let down my guard and trust him completely. I truly believed he was my soul mate. I wanted to marry him and have kids with him. I have never loved a man that much. We ended up moving in together and I was extremely happy. I did everything I could to make him happy. I was affectionate, supportive, loving, kind, cooked, cleaned. Well 3 years into our relationship I found out he was messaging a lot of random women online and on craigslist saying a lot of sexual things to them and asking to meet up. I also found out that he had been lying to me the entire time about being in the marines. For 3 years he had told me detailed stories, would cry tears and even showed me fake pictures. All of this absolutely devastated me. It was hard to wrap my head around. But I still loved him. He begged me to give him another chance and told me I was his soul mate and he made stupid mistakes he wouldn't make again and that he wanted to marry me. So I stayed and tried to work through the terrible anxiety and paranoia I had developed. It was very hard. He did not understand my pain and we would get into terrible fights and he would call me all kind of bad names and tell me he hated me. But when we weren't fighting he was very affectionate, sweet, loving, supportive. And we had many great times together and had a lot of fun together. But as the years went on I had caught him in a few more lies that he would try to deny. But ultimately ended up blaming me for it. It was an up and down rollercoaster and a mess but I held on to the man I fell in love with and the loving man that he was when the bad wasn't happening. But I started to become depressed. I wanted marriage, a home and kids one day. We had gotten evicted from 2 apartments because he was not good with his money and many times I had to put my whole paycheck towards rent. He always made excuses why we couldn't get married and it was always my fault because of my trust issues. One day we got into a bad argument and he lied to me and in that moment I knew he would never change. I left and went to my moms, blocked him and told him it was over and haven't spoken to him since. But I still loved him. It was the hardest thing i've ever done. I was in therapy and my therapist and all my family and friends said I needed to go no contact so I did. But it was extremely painful. I know I probably shouldn't but I still feel guilt over it.

So after the breakup a guy friend I have known since I was 7 reached out to me to offer some kind words or encouragement and told me he was in a similar situation. That him and his ex had just broken up and she was a narcissist and treated him badly and would say mean things to him often. That sometimes when they would argue she would hit him in the arm, etc and that he has had to restrain her arms before.  But they had 2 kids together. He wanted her to move out but she refused and threatened to keep his kids from him. So him and I talked as friends for a few months but it developed into us being flirtatious and talking every day. I looked forward to hearing from him every day. He really helped me during a time I was very depressed and would wake up crying every day. He was very funny and made me laugh a lot. He was sweet and caring and seemed like a good guy. Well once our feelings really started to grow one weekend I didn't hear from him. I thought it was odd and noticed he hadn't been on *** either. A few days later I found out him and his girlfriend had gotten into an altercation, and she accused him of trying to attack her and he was arrested. After speaking with him he explained that he had tried to be affectionate with her when they were home and she got annoyed with him. So he then tried to be playful and acted like he was going to pull her off the couch by her feet. She then stood up and started hitting him and then punched him in the face. He asked her to stop and she wouldn't so he told me he grabbed her by the shoulder near her collar bone and took her to the ground and he was over top of her for a few seconds yelling at her asking her why she hits him and treats him so badly. Then he got up and she got up and followed him into the kitchen still yelling at him, etc but ended up leaving and called the police and told them he tried to strangle her and she blacked out. So now he has some serious charges against him and they are still waiting to go to court. She did not have any marks on her neck other than a small reddish mark on the one side in between her neck and collar bone which would match up to what he told me happened. He is a pretty big muscular guy so I feel like if he really did try to hurt her the way she describes that she would have had some visible marks. She originally did not tell the police officer she was hitting him initially. But in their first court appearance she did admit to that. He knows that he did not make a good choice by how he reacted. He said she had been treating him like that for so long that he had lost his temper in that moment.  But says he never once attempted to strangle her or put his hands around her neck.  He has been telling me he wants to be with me and I had developed pretty strong feelings for him as well and feel like we had a pretty strong connection right up until this happened. Looking back I feel like it probably would have been best if I wasn't talking to him while they were still living together. But it genuinely started out as us just being friends and I had intentions on staying single for a while after my ex. I also believed whole heartedly they were no longer in a relationship. Otherwise I would not have continued texting him. And I even asked him multiple times if they were to ever try again to work things out to please let me know because I didn't want to come between that. But he was always very clear that would never happen. That he had tried many times with her but she wouldn't allow it. And she was also talking to other men behind his back. He said he told her all the time he wanted her out but she refused. But this whole situation has me stressed out and I honestly feel so lost at the moment and don't really know what to do. I don't know if I should just hang in there and see what happens after they go to court or how to go about this.