Ex is wanting to get back together

Long story short, my partner (43m) and myself (38f) have been together 5 years, we recently broke up. We have two kids together and are not married or engaged. We have had many ups and downs but this past year especially has been extremely tough. I feel as though I have a third child really, every celebration for me is ruined and I end up having a horrible day. When he is frustrated or angry he speaks to me horribly. My 3 year old has told him to stop yelling at me which is extremely concerning to me. He works from his parents place and stays there overnight every couple weeks. We live 10-15mins away. Every time I asked him to do something it was excuse after excuse. The icing on the cake to all this is that he told me that a year into the relationship he bought a ring but never proposed because every time we had an argument it put him off doing it. So he's happy having kids with me but wont propose because we get into an argument. Why would you tell someone that when you know it means so much to that person. It makes absolutely no sense to me. As soon as we broke up its like he had this sudden epiphany and he is saying that he is going to change the way that he reacts to things and speaks to me, that he wont work as much, he will help me out around the house more and with the kids, that he's taken me for granted, that he's scared to lose me, it goes on.

My issue is that we have been in this situation before and we keep going around in circles but he has never reacted to it the way he is now. Its usually a yeah I know and nothing's ever done. I personally dont think he ever thought I would leave. He is asking me to let him prove it to me, that he doesnt care if it takes a year to gain my trust back he will work for it because he wants to be with me. I personally think it will go back to the way things were.

What do you all think. Should I walk away or give it one last chance for a couple months, even just to try for the kids and see if we can get back to where we used to be.