In addition to other great (and not so great) advice here, consider testing for ADHD, if you haven’t already. I finally got tested and diagnosed pretty late in life, and started taking Adderall. It helps somewhat. In my brain, the noise made it difficult to focus on conversations, even 1x1, and part of that noise was constantly gaming out potential responses in real time. Now I am still slow, but have an easier time holding on to the conversation thread, and so pulling out an appropriate response from my memory. I still overprepare for every conversation, and try to have organized notes when I can. My patient wife got used to me saying that I need time to think through something. I then make a spreadsheet of potential conversation branches and decision options, and we end up having a much more productive conversation.