How can I get the help I need??

I’m so depressed all I think about is wanting to die since I was 14. I feel so alone and I tell my mom this but she just treats me like a little kid and rubs my back while I cry. I’ve told her many times that I want to die and she’s seen my scars from cutting but she doesn’t help me. She’s a good mom I just think she doesn’t know how to deal with a depressed person. I want help. I’m tired of feeling like this i want to be a normal 17 year old. if I continue like this I have a really strong feeling I’ll end up trying to kill my self