I need some advice, concerning my relationship with my Dad. And Getting abused.?

I am a 16 year-old boy who lives with his father and mother. They are happy together and the rest of my family and them get together. My Mom and I have a good relationship, but that could not be said for the "relationship" between me and my "Dad". I lived a very privileged life I guess compared to most. I was the star in my family whether it was sports, school, or anything else I was better than my other siblings. As well as the first boy to be born, so naturally my Dad took a interest in me. I soon became the only kid paid attention to, sure they'd go to my sisters choir things and my little brothers graduations but they would drop anything that my brother and sister had going on to come see me excel in sports or school. My Dad put so much pressure on me as a kid, and now as I am in high school I just can't keep my grades up and have been asked to not come back to my high school causing me to go to a different one. I feel like my Dad thinks way to highly of me and when I fail he doesn't know how to just take it as a mistake. He will yell at me all the time. Constantly yelling and telling me I am a loser just because I haven't done as well in school as I used to. He always tries to make me feel like ****, and over time I learned to ignore it. They are just words after all... I guess. Around 8th grade (I am now going into Junior year) he started to get physical with me. Pushing me holding my face down to the ground whenever a argument got heated. Then it progressed to throwing me down on the ground or into walls. To my clothes getting ripped by the shear force of him holding or throwing me, to bruises and cuts on my body and arms. To now where even when I am not doing anything but trying to do what he asks, he will still continue to yell and hold me down. Today, I asked him to stop yelling in my ear because it is the only ear I can hear out of he started to throw me around, he threw me on the floor and held my head down by pulling my hair and putting his knee on the side of my head. I proceeded to get up after I thought he was done, and he thought I looked at him with an attitude or something and threw me on my bed I tried to push him off and my hand was cut, along with my arm. Then he tried to hold my head down again with his knee hit my nose and caused it to bleed. And proceeded to knee my chest. I also learned to not fight back because It will just get worse. I know it could be worse and I have sympathy for those who it worse, but I don't feel that this is how parents should treat their kids. It's gotten to the point where I have to defend my sister and sometimes my little brother and even then I'll get abused. I look around at my other friends who do so many more bad things that my Dad would castrate me for and they don't get abused. Is this right? Could Legal action be taken? I don't exactly want to take action with the police or something because it would cause more stress to my siblings and Mom then they deserve. What should I do? What can I do, if anything at all.