Both of my XH's and my XABF have tried the same thing. It's all my fault, I'm destroying the kids, I'm only doing it for 'this' or doing it for 'that' reason. It was, like you said, a guilt trip. Not tears of what happened because of both our errors, but what's happening because I'm not willing to give it one more try.
I heard it said a million times but didn't really understand it until recently. They will try, do, say ANYTHING once they lose control. They (my ex's) lost control. Everything, I, was no longer in their hands. Suddenly they were faced with following instead of leading. It was "OMG, she's not under my every command anymore! Quick....look sick, upset, sad, whatever it takes to get her back under me!"
It's so hard not to fall for it. It's even harder to know the difference between real and "I've lost control of her" fake. I posted about it a few months ago, I felt so cruel by my "just not listening anymore" actions. I wondered, and still do sometimes, if his words were the truth. Did he really mean it? So I'd take it as real and give him one more chance. Just to find myself days later regretting it. Kicking myself in the butt for having fallen for it, again.
Hang in there. Focus on you and your child. Nothing else matters. I am the only person who has been there for my kids since day one. I've been there every night when they went to bed and have been there every morning when they wake up. I am the only consistent, reliable person in their lives. I don't pressure their fathers to do what's right. If he wants to, he will. But it's his choice. And someday my children will understand everything and it's not me they'll be upset with. Right now it is, they don't get everything they want. But eventually they'll learn that mom did the best she could and because of her they always got everything they needed.