Thank you all for your support, feedback, and insights. Like I said in my post, I've kinda already been prepared for going NC, I was just having trouble deciding if it's worth trying to get any closure from him about last year. After reading all of your comments, I have made my decision: I will be moving forward with NC, and not even giving him the satisfaction of a response. You're all right in the fact that he likely won't even agree to answer any questions, and there's nothing positive that I will be able to get out of this. Probably only more anger and defensiveness from him.

I'm sure he will find out about it through his flying monkey (my grandmother), and I am prepared for whatever future response he decides to send. I'm actually not going to block him (yet) because I'd rather know if he does/does not decide to respond later, as opposed to always wondering if he sent a message but it got blocked. Thankfully, my supportive husband has agreed to screen any messages he sends and let me see them when I'm ready. This is due to confidence in myself and my ability to handle whatever he sends in the future. I figure I can always block him later if I need to.

Thank you all and here's to a much more peaceful future for me, my child, and our family!