My Brother

So, I've been wanting to kill myself since I was about 6-7 years old. It got really bad when I started middle school, and I started self-harming and tried to kill myself multiple times. I'm almost done with Highschool now, and I have recently realized that I don't want to die, that I just want help. I was planning on asking my parents for any help they could give, but today they found out my youngest brother is suicidal. He reached out after feeling like this for about a year. He's only in 8th grade, and I'm not upset with him or anything, I just feel empty and isolated. I know the downward spiral he's going through. My parents have always cared more about my brothers than about me. They have already scheduled a therapist tomorrow for my brother, even though they don't believe in mental illness. They've found my razors and knives before, but just threw them away/ignored the obvious issue. They have been abusing me for as long as I can remember, and the only reason I haven't seeked even police help is because i had to protect my brothers. I'm the only one they physically harm, and they love controlling and manipulating me. I'm like their personal ragdoll. I always stayed so my brothers wouldn't get hurt. I'm sorry I couldn't protect my brother from the same inner demons I face, and i feel like this is my punishment. I know that if I tell anyone my feelings right now, I would be written off as an attention-seeker/liar. I don't know what to do anymore. I'm so overwhelmed with emotions and can't stop crying. I've always worried for him, but this hit so close to home, and I just don't know anymore.