Well, there is usually not a lot of inner dialogue in the middle of a sword fight. The slow part of the brain that mulls over stuff switches off and the fast part of the brain the tries to not get stabbed takes over. So inner dialogue in a scene like this would generally be inappropriate. It would not be true to life and that is why the attempt to do it feels like a disruption and destroys the pacing.
Secondly, your job as a writer is not to show emotions. It is to create emotions. In a properly constructed story, the reader knows what emotions a person is having, just as we do with a person in real life most of the time, based on what we know about them and the circumstances they are in.
Generally speaking, the only time you want to show emotion is when it is contrary to the emotions that the reader is expecting. The guy kisses the girl and she burst into tears. The doctor hands the baby to the mother and she pushes it away. In these cases you are using the show of emotion to surprise the reader and create tension. But for expected emotions, you should let the setup take care of them for the most part.
By the time you are in the middle of an action scene, in particular, it is too late to create emotion. The reader should be having an emotion and projecting it onto the character because the action which they have been dreading/hoping for has begun.
So once the action starts, don't interrupt it. If you want the reader to feel emotions about the action, or to know that the character is having emotions about the action, set that up first. The action scene is where you pay off the emotional tension you have created in the build up.
Emotion comes from set up. In the classic horror movie scene, we are first shown the killer hiding in the basement. Then we see the cheerleader going down the steps looking for her boyfriend. Without the setup, it is just a girl in a short skirt going down stairs. But once it is set up, by first showing the killer hiding in the basement, it is an incredibly tense scene, and we are on the edge of our seats shouting at the screen.
Don't try to do everything at the sentence level therefore. Most of the effects in fiction don't happen at the sentence level. They come through setup and payoff. A good action scene does not need any interior dialogue or exposition of emotion, because, if it has been set up properly, we know what the hero is thinking and feeling in the fight. And if it has not been set up properly, then nothing you can do in the text of the fight scene is going to make up for that lack of a proper setup. It is just going to interrupt the action, slow the pace, and drain the drama from the scene.