Great question, and welcome to the forum, I'm new too! Maybe we can help each other - I dissociate so it's pretty easy for me not to feel emotional about something, ha ha! Sorry, not helpful.
I took another post's suggestion earlier today and worked on mindfulness while my BF was talking to me about an argument we'd had this morning. I usually get hyper defensive and shut down and stop feeling anything, but instead I made myself stay present by focusing on the grass and the gravel and the bugs and everything that was going on around us as he was speaking. It helped me to just sit and calmly listen and absorb what I could. I told myself I wasn't going to take this as a personal attack, he's allowed to voice his feelings and it doesn't mean I'm a bad person because he's unhappy with my behavior. And it worked, actually!
I'm not sure if mindfulness could help you - but maybe if you focus on something specific that's happening in the moment, it might help you not to focus on an initial, emotional, gut reaction and give you time to process your thoughts before you act on them?