I posted the other day about my NC with my BPD mother and my likely BPD brother who has been serving as a flying monkey for my mom-learned that term from here

My brother had sent an angry text in the middle of the night, to which I chose not to respond thanks to support I got from this group!
He reached out again today and I attempted to use some strategies I'm learning from the Margalis Fjelstad book and information from this site.
Below is my conversation with him and I'd appreciate any feedback on what I could have done differently or skills that might be helpful for me going forward. I know the conversation didn't go great, especially towards the end. I feel like I've got some very shaky training wheels on my bike with the skills I'm trying to learn and figuring out how to keep my bike upright as I navigate stepping out of the Caretaker role in the drama triangle!
Text from the other night that I didn't respond to:
How long are you going to punish mom and play these foolish games? You can get mad at me and say its moms fault blah blah blah I don't care who's fault it is. Simply don't give a f***! But I do know that if you continue down this path you will regret it. Mom is not well it's questionable if after the next few months she will be able to get out of a wheelchair. Stop your fish selfish games and talk to her. I don't have your side on this I think YOU are being ridiculous.
Today's conversation:
Brother:So just nothing huh? No response? Is this really the way you want to deal with this?
Me: No I am not going to respond to aggressive text messages such as the one you sent the other night
B: Ok well it seems you don't want to respond to anything.
M: Why do you feel that I don't want to respond to anything?
B: Why are you so unwilling to talk to mom?
M: I'm not unwilling to talk to mom
B: All she knows is that you were angry she called the police for a wellness check...
B: You haven't spoken to her in months even when she has reached out.
M: I have responded every time she has reached out and also reached out to her
B: When did you reach out to her?
M: Yes I was angry when she called me 30+ times, texted 10+ times, and called the police on me when I was away from my phone for a little over an hour
B: Ok so that's justification for not speaking to her for months?
M: Like I said I have responded every time she had reached out and also reached out to her
B: When did you reach out? It wasn't an hour I've seen the messages and conversation history. You said you would call her never did she got concerned and then texted you then sure she texted and called multiple times before she called the police.
B: But why does any of that matter it was all done out of worry for you. Why be so angry that you don't communicate for months?
M: I didn't say I would call, it was about an hour and 20 min, it matters because that is out of control behavior to call the cops after not being able to reach someone for less than 2 hours, and I have communicated with her
M: If mom wants to talk to me about any of this she is welcome to, but I don't understand why you are getting involved in it and becoming angry with me
B: So there was a misunderstanding about you guys talking that led to her becoming worried and calling/texting that resulted in calling for a wellness check. I get being angry for a week or even two but really 2 months have gone by and you can't pick up the phone to resolve this? You really think mom is in a position to call you after this I mean in her mind calling you is how this all started.
Why am I angry. I'm angry because you know what this does to mom you know how this type of family conflict impacts her. She had a good opportunity to make some very substantial changes with this medical leave and heading into retirement. Instead of focusing on those changes she has been worried day in and day out about her relationship with you. Of course it makes me angry when this could all have been resolved through you simply reaching out and having a conversation.
M: Mom is capable of solving her own problems, if she didn't want to be worried about her and I's relationship she could have called to talk to me
B: Typical for you to not take any responsibility for how your actions affect others. Like I said why would mom call you when calling you started this in the first place.
M: Calling me 30+ times is what started this, that doesn't mean she can't call me if she is wanting to discuss the situation
B: I mean you make me even feel like I'm a burden to you when I call. Can't remember the last time you chose to call me that wasn't simply a return call or text to see how I am doing.
M: I'm sorry you don't recall times that I have called you that wasn't just me returning a call or text
B: Ok well it's clear you don't want to accept any responsibility. That is certainly up to you but it doesn't meet my expectations of a relationship I want to continue.
M: What responsibility do you want me to take? I don't keep track of who calls or texts first between us. Do you initiate contacting me more yes, but that doesn't mean I never initiate contacting you
B: Just actually care about your family and treat them as if you do. That means not treating them like a burden and actually taking an interest in what is going on in there lives even when you don't have your own news or exciting events to share. I have called you or texted multiple times to see how you were doing. The same is never returned and when I do start talking about something often times it's met with you having to deal with dogs or I just got home or...your too busy to have a real relationship yet you will cry to me in my kitchen that we used to be so close and have grown apart. Then I try and just get the same your a burden I have to deal with occasionally response. Well I'm not cool with that.
B: Yeah let me break out my record log that's what this is about...
M: It seems you feel I never take an interest in what is going on in your life, but I don't feel that that is the case. When we talk (regardless of who initiates) I am curious about what is going on in your life. I do not view you as a burden, but I don't particularly enjoy talking on the phone to anyone. To stay connected to people though I do talk on the phone, but to be on the phone for hours is not enjoyable to me. I'm sorry that me having to deal with the dogs or just getting home from work makes you feel that I don't care about you. It has nothing to do with how I feel about you, those things are simply tasks going on in my day which are hard for me to talk on the phone during. One challenge that I have is that despite me trying to talk with you more is that whatever I do doesn't seem to be good enough and I feel like I am just waiting for you to get upset with me.
B: Again just more excuses and taking zero accountability for the way you make people feel. I don't like to talk on the phone...then how am I supposed to interact with you? I have responsibilities including dogs and work...yeah we just sit at home with no responsibilities to attend to. When do you try to talk to me? I am the one that was pressed on our relationship through you crying in my kitchen. Then when I try to make a more concerted effort to re-establish that relationship you tell me "I don't like to talk on the phone."
M: While I don't enjoy talking on the phone, I do it because I understand that is how to stay connected to people so I'm not sure why you're asking how you're supposed to interact with me. I do talk to you on the phone and I text you. When we are talking and you have things to attend to we end the conversation, I don't take it personally that you need to do something else. Previously you would get angry that I never answered when you called or called you back. I have made a concerted effort to work on that, but now you are upset that I'm not the one to initiate the contact as frequently as you initiate.
B: You know what you win... take your win and have zero accountability cause it's clear to me that defending your actions and the way they have impacted your family is what's most important to you. So you WIN here's your prize (he inserted celebration emojis). Hope it was worth it cause what I think you have done to mom is cruel and I have nothing more to say.
I did not respond after this since I had made it clear that I would not respond to aggressive messages from him any longer. Also for reference the time I was crying in his kitchen was after my father died and he got angry that I missed his phone calls when I was cleaning out my father's house.