Living in fear that your father will hurt you because he has in the past isn’t healthy. You list your age as 17, which means you may be close to leaving your home. I would highly recommend you contacting Child Protective Services (CPS) not to repost all of this, but to ask about your options. Here is where you can get this information, and here is the information about each district within your state so you can talk to someone close by.
The important thing is that you have someone to talk to and help if need be. The fact that you have a physical disability, which may limit you protecting yourself, is an important factor. In addition, it doesn’t sound like your mother is much of a protector, and that she may be someone to fear as well.
Talk to the people who can most help you and your siblings. You’ve done well reaching out here — now it is time to continue by reaching out to the CPS.
Wishing you patience and peace,
Proof Positive Blog @ PsychCentral