I'm sorry it happened. If it helps, you're definitely not alone. To this day, I wonder why my dad even bothered to marry and start a family, if he was going to treat us so badly. I felt like the only kid in the world who wished that my parents would get a divorce.
It's hard to have sympathy for anyone who's been abusive to you, but more than likely, he was abused and mistreated by someone too. And now, abuse is the only way he knows how to relate to anyone, because he wasn't properly nurtured as a child. Regardless, that doesn't excuse his behavior towards you and your mother. He still hurt you.
However, once you start to try and make sense of why these things happened, it makes it easier to heal and recover. One of the most hurtful things about being abused is not knowing why. Why did he do that? Why didn't he handle that situation differently? Why was abused? When you start seeking the real answers to those questions, what you find may surprise you.
When I think of the violent man who beat and intimidated me as a child, it's hard to feel compassion. But when I think of the small, vulnerable abused child he once was, it's easier to make sense of why he did what he did.
Abusive adults tend to be very childish in many ways. They're stuck in the same immature mentality as a kid, but unfortunately, they have more authority and responsibility than a child could have. Imagine if 8-year-olds could be parents? My dad did a lot of things to me that kids on the playground did. Namecalling, pushing, hitting, tantrums, yelling, throwing things. At least with another kid, I could defend myself. With him, I was too terrified to do anything but stand there and take whatever he dished out. I wouldn't dream of hitting back or even running. I didn't want to risk making him angrier than he already was.
Think about kids who burn ants with a magnifying glass & pull legs off spiders. My dad was that kid, except he had children instead of ants. He had a little "game" he liked to play with us. He'd yell at us to come over in the voice he used to call us when we were in trouble. He'd shout at us to "cry!" Terrified, and wanting to avoid a beating, we'd cry. If he thought we were faking, he'd get more threatening and loud and scream "cry real tears!" He'd never hit us, he wanted the satisfaction of knowing that he could bring us to tears through sheer intimidation.
As we'd stood there with tears rolling down our face, bodies heaving in sobs, he'd give us the most wicked, sick smile. After he was satisfied that we'd suffered enough for his twisted amusement, he'd coldly dismiss us, as if we were the most pathetic subhuman scum in existence. He was asserting the fact that he could do whatever he wanted to us, and there was nothing we could do about it.