I have been with my fiancé for almost 6 years. Throughout the relationship we have struggled through numerous issues, some have been overcome, and others recurring. One recurring issue is trust, mainly on my part. I have been on a dating site, I have threatened to leave to the point of calling crisis centers believing he was abusive (which was completely untrue) and I spoke with my mother about it at the time which painted him in a horrible light in her eyes after he spent so much time trying to win her over. Recently he has been helping a female friend from work with a lot of favors. He has been waking up early in the morning after working very late at night to drive her to work (which takes him a couple hours in total), he has helped her apartment hunt, and has been to her new apartment to help clean it for two nights (between 4-6 hours before he was home). I was feeling insecure about everything and talked to him early in to these favors happening. He assured me nothing was happening and laughed it off thinking I was silly to think there was anything there. My insecurity did not fade and only increased when I saw texts like "sweet dreams" and "I miss you". I had asked about the "sweet dreams" text when he got it as I was right there when he got it, and he said that's just how she talks to people, it's just her character. I still wasn't trusting and so when I saw the "i miss you" text I almost saw red. I was shaking and almost in tears. I ended up responding as though I was him and asked her to call me. When she called I answered telling her it was his fiancé and asking why she was saying the things she said. She said there's nothing there and we hung up with me feeling guilty. When I presented it to him he already knew it ad happened and it became the last straw. He had told me a few weeks before this that he was only 'content' in the relationship and wasn't completely happy. Now he is pretty much ready to leave. We have not even touched really for the last month and he has told me he doesn't think he can let himself risk being hurt again. He has asked me to think about the relationship objectively and think about whether it is a healthy relationship and why it should be saved. I feel like I am being as objective as possible in my reasons but fear if he disagrees that he will think I haven't tried to really out thought in to it and we will be over. We still say "I love you" and he still lets me kiss him goodbye (on the cheek) but he hasn't worn his ring in weeks, and has said nothing has really changed for him since his first conversation with me. I really don't know what to do anymore. I really don't want to see this end. I am confidant I can kick the insecurity and start trusting him, but he can't be convinced. Anything I do now looks like it's out of fear of losing him. We have two kids together and a 1 year lease, he says that's the only reason he hasn't left yet. Am I fighting a losing battle? When I asked him if he could think of a positive reason to stay he said "in a way yes", is that a sign of hope?

From what you described at the beginning, those were hurtful things, why he stayed I don't know.
Why you would stay and have two kids with someone and no marriage, I don't know. 6 years and he's your fiancé? He is your babies daddy.
I can't imagine that man is not messing with that woman, that sounds pretty funky to me, but your whole relationship is kind of funky.
Let him go, make sure he pays you child support.