when to contact cps

all 15 years of my life I have been told things will get better, well they haven't and that brings me here. My two sisters and I (one 1/2 sister) have suffered emotional and physical abuse from our parents all our lives. My older sister was finally able to get away from it after turning 18 but my younger sister and I are still living with it everyday. I am scared of leaving my younger sister behind even though we dont have a great relationship because I think it might become worse for her. I have thought about this alot and I think it is finally time to get help, but I have come here for a second opinion. I have relocated many times in my life and from a young age I remember my parents never really being around. They both had drinking and gambling problems and would go out to the casino after work and on weekends and leave us in the care of my grandpa or my older sister. When they did come home they were usually fighting about something typically money, I remember one night where it got physical with my dad pushing my mom and my mom punching him in the face giving him a bloodied black eye. my dad went away for a few days after that. my mother would hit us with almost anything from spoons to slippers. we would sometimes be left with welts from where we were hit especially when a belt was used. my dad would hit us with the belt too but not as much. my mom would drag ass by our hair and we often get punished for innocent things such as throwing up. from a young age my parents have on/off talked about divorce and asked us who we want to live with. they often try to make the other look bad and make us think its all the other ones fault. there was one instance I had to be around the age of seven where on a road trip my mom to see family, got out of the car and hit me in the face with her ring on and gave me a busted lip. I remember this clearly because I can recall the awkwardness of my grandma and aunt seeing and knowing what had happened but no one wanting to talk about it. after moving around the age of ten things weren't as bad, my mother would still have outbursts about little things like chores not being done right. there was one time I remember being on the floor in the corner of the kitchen and my mom standing above me threatening to bash a strainer I hadnt washed into my head. there is always yelling and screaming in my house and I dont think that will ever change. my mom has always spoke negatively about me, calling me a whore or bitch. my dad was never as bad until his mom died he started drinking so much he was drunk every night and also trying to kill himself. he was always scary drunk and chased me around with a knife once. a little after that things didnt get much better he lost his job and had to go to jail for sexual assault on someone alot younger than him. I didnt really know what to think that whole situation still confuses me. we had to move again after that but still nothing changed. I started hanging out with not so good people at our new home and got in trouble alot. there was this one time my dad found out something he didnt like and he pushed me to the ground in a chair and started kicking me in the head with his boots on. after my mom lost her job there we moved again after only a year. the new place we moved to was very nice I liked it alot and I got out of all the bad stuff from the last place. while we were there my dad had to go to the er and ended up almost dying from all the alcohol. he stopped after that (about a year ago) because he could very well die if he keeps it up. I lived in that place for two years and the hitting continued but not as much and not as bad. my dad got worse the older I got. he was mad about something silly like me not taking out the trash and broke things in the house and punched a hole in the wall. I went to school crying alot even on birthdays because they just never treated me very well. there was times where my dad would get mad in the car and slam on the brakes on the freeway or speed up super fast almost causing an accident. me and my sister got in a dispute about something and my mom abruptly pulled the car over on the highway and threw my phone in pieces out into a field. my parents made us move yet another time just recently and things have not been good since I have lived here my parents are constantly fighting and I do not get along with my dad at all. he makes me feel like I am just some druggie slut who is not worth his time. even though I have always done quite well, always get all a's in school, stay away from drugs and do the best I can for myself. I had a boyfriend at the last place and I think that might be why, he has always been very protective about that stuff with all three of us. but we never did anything wrong and we dated for over a year. I have always been the one put at blame for the family being the way it is. I have attempted suicide in the past because they made me feel like they would be better off without me. although now that I'm older I don't think thats the best solution, I was young and helpless then. I know my younger sister already suffers with anxiety and mild depression and I am scared of whats going to happen once I am gone, if it wasnt for her I would probably just suffer through these last few years and go on with my life, I have always been exceptional in school and sports and I am very competent so I know I can do well in life. despite all this we do have good times, when we go on a hike or a trip. sometimes it feels like everything is good and this really isnt that bad but then something happens that reminds me. my mom hit me today and dad talked about kicking my face in after a big outburst by them today. my mom apologized later on but nothing from my dad after the harsh things he said. I have called a hotline for these type of things and they said to contact cps but I feel like they have to say that. I am scared of whats going to happen to my sister & I if I do end up contacting them. I often here it just gets worse. sometimes I feel dramatic and think I should just carry on with life and try to avoid this as much as I can but I realize the harm they are doing on us has lasting affects. I don't really know what to do, should I just tough it out these few years I had left or should I tell someone. it really is a negative household 90% of the time and I wish it wasnt both of my parents that are this way so that I could just leave with one of them. maybe they are just bad for eachother and thats why it has been like this. I really just think some people arent meant to be parents though. even if I do not end up telling anyone what good way are there to handle people/situations like this. I dont know what to do.. hopefully I can get some helpful advice from here. anything helps thanks