Do I have depression?

Every day I go in and out of feeling worse than shit and like there's no point to move and feeling okay and maybe even a little happy. There are almost no days when I don't have negative feelings for at least part of the day. My family makes me feel like absolute crap about 75% of the interactions I have especially my mom. But I try so hard to be better somehow so she doesn't get mad at me but I don't even know why she gets like that to me and I've tried talking to her about how I feel and it always turns into how my feelings upset her which makes me feel even more like crap. I used to cut a lot. On my thighs and my mom found out and started screaming at me about how my feelings are completely irrational and I'm being stupid. But I can't talk to her or I'll feel like crap and she won't take me to a psychologist because she thinks there's nothing wrong but sometimes I really feel like I'd be better off dead. I don't really try to act on that thought anymore because I don't feel like I have the energy. I used to feel like cutting was the only way for me to express my pain. I have close friends that I talk to but I never feel better after talking. Am I depressed? Do I need help? How do I get it since my mom won't support me in that way? A school counselor isn't really an option because my mom teaches at the school I go to and knows my counselor and all my teachers. I don't really have any adults to talk to. I don't know what to do and I don't even know if this is depression. Someone please help me.