There are so many reasons why parents fail their children, why they abuse the angels in their care... The most important thing is that you know that it is not your fault... You may never know why, but don't let that stop you from your healing from abuse that was out of your power to change. Read and learn as much as you can about your issues... You have your entire lives in front of you and you do have the power to effect change for yourselves now... You are worth it!!!