He said he cheated on me so I would divorce him

Here's the story again
My husband cheated on me with his ex girlfriend. I found out because he blurted it during a fight. At first he tried to say he was just mad and made it up but then he admitted it. After that he treated me so horribly and said some of the most horrible things to me. I was already devastated enough. We had already been living in two different places because we lost our apartment when this happened so I guess it was easy for him to do.

After a month he told me he still wanted to be with me and didn't want a divorce. So we tried to make it work but I just couldn't trust him and we kept having issues. For one I could tell that he wasn't being honest about what really happened with him and his ex.

We ended up getting into a horrible fight and then his ex called me. She called me because I had left her a message on her answering machine. At least she told me that was the reason why she called-to address my message. She told me that he had spent the night over her house several times during our marriage but that was the first time that they had had sex. She told me that he told her horrible things about me and that he told her that he wanted to be with her and she said that she didn't want him though even though he constantly told her how he wished he was still with her. After i confronted him on this he became very hurtful again. He told me that I was dumb and that she did exactly what he wanted her to and that he had cheated on me several times during our marriage. He also said a lot of other hurtful things.

I ended up filed for divorce and today we were talking and he was trying to explain to me what happened and tell me that everything she said was a lie and that she always told him that if I ever contacted her she would tell me the most horrible things and that he doesn't want her.

I don't believe that he really believed I filed for divorce at first. but then he kept trying to convince me that she was lying and to listen to him because it didn't go down like she said. I couldn't believe his lies. Thats when he said that he used her as a pawn. That he didn't want her he used her so that I would divorce him. Then he hung up. A couple minutes later he called and told me that he just received the divorce papers in the mail and that he was soooo happy and he was asking me where is he supposed to sign and just constantly telling me how happy he was. I told him I was too. He then just hung up on me so I called back and asked him could we be friends and he told me he would think about it and hung up then I text him and he told me that he will never text me back or talk to me again. I don't understand this...we have children.

I am so hurt right now...because it hurts that he would plot that up just to get me to divorce him. My mom doesn't believe his fake happiness and says that he is just trying to save face and win the upper hand by saying this is what he wanted all alone.

My husband was always emotionally abusive to me. I honestly believe he is a Narcissist. I never know what to believe when dealing with him. What do you think? i know it doesn't matter why..I just feel I need some clarity of at least some truth