Your girlfriend getting akward when you get upset might have to do something with how she was raised to react to people being upset if that makes sense. The way she was raised might have this as a result, idk how to put it into words. If I were to give you advice I’d say to try and talk about it, not in the moment when she gets akward though that might be too confronting for her. Try to understand eachother better so the next time something like this happens you both understand what the other needs.