Mental Preparation

Hi, I want some advice about mental preparation and about when to attack and when not to attack...

You know, I had some problems recently:

Some days ago, I heard a strange noise close to my house, and went to check. There was a guy trying to force his wife into entering the car while se was screaming that she wouldn't go. I asked what was happening, and he suddenly punched my face.

I have a fairly good resistance, so I didn't even feel any pain, even thought I fell into the ground (Probably, because I'm very light too). Confused, I tried to fight back, but I took lots of other hits and was very hesitant to punch him.

I punched his face once, but apparently not too hard, then he started to be a coward and tried to bring weapons into the fight (Probably a Knife, but he didn't take it out of his pocket after he grabed it in his car.)

His wife was trying to stop the fight, and convinced him to get in the car and go away, while I called police.

I'm very confused about it, I was TOO calm for a fight, but was hesitant to attack.

Some days after, I had a discussion with a friend of mine, we work together and he has a higher position than mine.

In our discussion, instead of argumenting he was using his position to try to impose his opinion over mine.

In the end I ended up punching him, even tough I didn't use my full force, I'm very sorry about this, and he's very angry with me and things aren't really good here.

I realized that I'm NOT mentally prepared to fight, I'm too aggressive on my friends, whom I should be more humble, and really weird about my enemies, like I'm possessed by calmness and devoid of emotions, while my mind gets confused and I become hesitant....

That night, I could have called the people in my house, they would come quickly, render the guy unable to attack and resolve the situation, whitout that woman having to go with that guy she didn't want to go, instead, I called the police, that would take hours to come, while he was already far away.

I want to learn some more philosophy, self-discipline, and learn the best way to act in fight situations.

My friend was right after all, I should have respected him, but I didn't...

And that guy should be the one going to the hospital later that day, not me. (Well, I was just for collecting evidence, not because of the pain or anything, but, I think I could defeat that guy, he was a coward after all.)

Well, do anyone have any tips where I should look? What should I learn?

What would help me?

Sorry for the long post and for getting ths out of my chest right here, but I will be very grateful for any help.

Thanks in advance.

RMisaki.