I think there is a lot to be said for recognizing and embracing your emotions. Just yesterday, my INTP got ruffled at some offhand thing I said and it was obviously written all over his face. He withdrew and his pupils got very large. He answered questions with one word only and seemed almost stunned at everything I said - like he couldn't grasp what I was trying to say. I rolled my eyes and ignored his behavior but I decided to put him out of his misery when he turned down food and said he wasn't hungry. I knew damn well that he must be hungry even though he doesn't realize it, because I've been studying his eating and sleeping patterns. (Creepy, yes I know, but how else am I to know things unless I get empirical evidence and analyze it?)
Anyway, when he turned down food, I called him on it and said that he was upset with me and he needs to recognize it and almost embrace his annoyance at me. And I told him the exact phrase that I said that made him change all of a sudden. When it was brought to his attention, we were able to talk about it and move on (and then he ate every scrap of food on his plate, thank you very much) and all was well again. He is so perfectly predictable.
My suggestion is to study yourself the way I study him. If your heart starts to race or your body temperature rises or you feel like the words are all echoey and incomprehensible, chances are that something is affecting you. Take a deep breath. Stop and accept it, think about what it is and deal with it. It's usually not as a big of a deal that you think it is. Use the power of Ne to figure out another way to look at the situation.
Just because you've never dealt with that situation before doesn't mean that you can't deal with it now, even though you have no Si point of reference. Just try to create one in that moment knowing that you will always have this experience to fall back on and learn from in the future. You are going to fuck up occasionally. So what? You have to crack some eggs to make an omelet. No one is perfect and no one expects you to be, either.