OP, I'm sorry you are having to deal with this again. He has lurched back to denial, because Friday is approaching, and he hasn't even told his ex yet because he thinks he can change your mind between now and Friday.
You need time and space to figure out what you want. Him reappearing again and again is preventing you from having that time and space. Whether or not he realizes what he is doing, the result is DELIBERATE.
He is NOT thinking about you (singular) at all.
He is not even thinking about you (plural, as a couple).
He. is. thinking. about. himself. only.
He needs to sort this out by Friday. You do not. This is not your problem to solve.
Your problem to solve is "how do I feel, and what do I want?" You will NEVER be able to figure this out in a week, but you won't figure this out in 10 years, if you don't ever have the space and time to deal with this.
Now that he is in denial again, this is forcing you back into denial: about who he really is, what you really want, how you want to live. The man you have seen at his worst is who he is. A good man does not call his partner the foul things he has called you. A good man pulls his weight, contributes, compromises, and listens. He is none of these things, he has done none of these things.
You don't want to be cruel. Saying no is not cruel. Keeping firm boundaries is not cruel. He's not a toddler, he will manage, but you need to be firm and consistent, as though he were a toddler.
He's not hearing you, and he doesn't want to hear you.
Please read back through your posts. You have not been lying to yourself. We who have responded to what you have told us have not been lying to you.
You are in pain, grieving, confused, and very, very tired. All of this is NORMAL. But you want to feel good again, so you're grasping at anything that does that. Sitting outside your house with him for 10 minutes makes the pain go away for a little while. A breather for you, time to pretend that he might have changed. Sitting outside your house for 10 minutes with you makes HIM think you are going to give in.
He will not change. The reasons you ended the relationship are still there. The same reasons.
If you want time and space to put your life back together, you need him to go and leave you alone.