I'm so sorry you have faced this situation.It hearts reading it, I can't imagine how painful it is for you. In your shoes I wouldn't continue the relationship, it's terrible to be treated like that being a mother of his children.Every woman is strong enough to be independent. Yeah, I know you have kids and work, and it will be really difficult to put all things together but remember - you must be happy first. If mom is happy then children are happy too.
I was also cheated. It happened while we were getting ready for our marriage.I suspected that things were wrong when started spending too much time ""with his friends"".I tried to know some info in his messengers but he put a passcode to his phone which was really weird.I didn't want to ask him about it cause I was scared, we had our marriage soon. Then I read hundreds of articles how to hack his phone and to read messages. Maybe it will also help the girls who read this and have the same situation. When I saw some of his messages in Snapchat I understood everything and showed it to him. My ex didn't even resist.He announced to me that he suddenly understood he was poliamorist and he'd like the other woman also join our future family.Sure thing I couldn't bare such a disgusting attitude to me and moved to my friend right after out talk. And now it hurts not even of his cheating but of his cold face looking on me and saying it with a calm voice.