moving sounds like the old chestnut - treat her badly till she breaks up with you, and shift the guilt onto her. It's a teenage thing some men never grow out of. This approach - him breaking up with you because he's treating you badly and sees it, is just another way of pushing the guilt off him onto you - 'I'm actually a nice guy, breaking up to be nice to you, as otherwise I'd be even more shit to you than I've been'.
As for the ExP - there were reasons for the split I presume.
It's tough, dating after you've been together with someone long enough to have kids. It's either that you find it difficult to trust someone after being hurt, or possibly in many cases expecting 'dating' to turn into the kind of relationship you had in the past where you want to spend your life with someone.
People who've never been married, never had kids with someone, don't know what it's like to do that, so those of us who actually would kind of still like to do that, it's even tougher to compare the random strangeness you find when dating new people and comparing it to the best bits of the person you were with in the past, when you thought you'd found 'The One'.
Bit of a bugger, really