I haven't studied any martial arts but i have tried to improve my form, balance and reaction speed by exercising on and off for years. I feel capable of dealing with most situations in which i am forced to act but i am missing something vital. I cannot be offensive only defensive. I will give a prime example. A few weeks ago my wifes ex hit her as i walked into the hall way. She is pregnant which he was fully aware of but he is very unbalanced. Witnessing this i immediately jumped between them with my back facing him. He was swaring and swinging for her over me like an animal. The kids were screaming and he was completely out of control, frothing at the mouth even. Any way when he didn't stop i shuffled backwards to make a gap at which point he put his arms around my throat and tried choking me. When this didn't work he pulled me out of the house and threw me in the garden. Thought i would mention he's a foot bigger than me and i can only guess at how much heavier but i am very dense. Still as i said he had thrown me on the floor. He ran over to me and climbed on top of me. He then started bashing my head into the ground and punching me in the face which i dodged nearly all of. Getting up to set on my wife again i jumped up and ran between them to again make a barrier. He was tring to choke me again and screaming nasty stuff in my face not a foot from the kids. I was telling him that he wasn't achieving anything and to leave but he was frothing at the mouth still where he had lost it completely. I managed to break free and ushered the wife and kids into the house. I followed and we shut the door at which point he screamed through the door a bit then left. We called the police and he was arrested. He is awaiting sentencing. Not once did i aggress him. I was completely calm through out the whole assault which lasted a couple of minutes and my wife was very proud. She said she didn't know any man who would have done the same. I didn't lay one finger on him apart from to deflect his punches aimed at my face. I did take a few hits and suffered a few scratches and bumps but nothing serious. My problem is that i put my family at risk by not aggressing. I did not want the kids to see me hit their dad but it's not an isolated case. I could have stopped him very easily i am sure if i hadn't refused to fight back but something stops me every time. I have a mental block which doesn't allow me to use what i have taught myself and i am worried that if a situation ever arose where i had to act that i might not be able to. What can i do? How can i gain the ability to fight back as i am sick of being abused by those who take advantage of my walk away nature. Can someone shed some light on my problem, please?