[LlamaLlamaDuck]

Hey Taylor! Welcome to TeenHelp!

Self harm can be very difficult to deal with, especially if no one knows, and I'm sorry you have to go through it. Although it does help you to cope and as you say, stops you from doing something worse, it is dangerous. It's very easy to lose control or go just that bit too far one night, you know?
I think you should take a look at the Alternatives thread. It's a big list of things you can do instead of cutting. Not all of them will work and it can take a while to find one that works for you, but it can be well worth it if it means you can reduce, or possibly stop, the amount of harm you're doing to yourself.
Another awesome thing that's worth checking out is The Butterfly Project.

The self-harmer simply draws a butterfly on their place(s) of self-harm and if the butterfly fades without them self-harming, it means it has lived and flown away, giving them a sense of achievement. Whereas if they do self-harm with the butterfly there; they will have to wash it off. If that does happen, they can start again by drawing a new one on

Of course, these are just ways that you can reduce/stop your self harm. Ultimately, no one can make you stop if you're not ready to.
Does anyone know about it? Sometimes talking to someone and letting them know what's been going on can really help because it means you can call them or talk to them whenever you feel the urge to hurt yourself and explain how you're feeling and let them support you.

I really hope this helped you a little. PM me if you ever want to talk.
-Nat