I don't want to put doubt into your thing going on, but if I could go back in time and tell myself some things after my break up, one of the things I would say is when someone says they're done, that means they're done with the drama and to try and bring up any stuff that causes them to feel upset or uncomfortable or feel like they're being pulled back into a place they thought they got out of...is just not a good idea. It's fine if you want to apologise for things you did wrong as long as it's a genuine apology and that can actually at times lead to reconciliation, but only you can know when you're interracting with him, whether he wants to get into that stuff or not. Sometimes you just have to show someone through your actions that you're sorry, and that can mean just giving them the apology and then giving them space without going too much into detail or starting a conversation that they don't want. So don't bring up the negative past, just admit your sorry about it but don't go into it in detail because instead of them thinking you've changed, they'll just end up thinking about the times where you messed up and that's all they can really think of and it's hard for them to believe an apology when they don't get a chance to see the change. That kind of conversation is really for inside a relationship as opposed to outside a relationship. Just have no expectations of him suddenly changing his mind based off your apology, but let it just seep into him and for him to sit with it.