I need help

My life keeps falling apart when I think it’s getting better. I’ve struggled recently with friends; I feel so used by them. My friends only really hang around me when they need me, and it makes me feel unimportant. This is like all my friends too and there’s not many. I feel lonely a lot, and it makes it worse when I try to reach out to people for help and I’m shut down. Besides friends, my family life is nonexistent. My dad and I hardly ever speak. I feel very uncomfortable around him, and sometimes I never see him. I’ve tried over and over, but I can’t connect with him. Then my mom. I love her, and she’s supported me, but she gets angry easily. That’s not a big deal, except when it comes to my brother. My brother has Tourette’s and ADHD, so he acts out a lot. Recently though, it’s gotten bad. He’s been brought home by the police, left the house without telling anyone, and he’s been blatantly ignoring my mom when she tells him to do something. Tonight she got angry in a way I’ve never seen before. I got so scared I ran outside and even contemplated calling the police. I’ve never felt so alone because I don’t know who to reach out to and now I have to stay out of everyone’s way at home. I haven’t dealt with my depression for a long time, but tonight I thought that if my life doesn’t get better and less lonely in the future, I’d probably take my life. I just need some help figuring out what to do. Please.