First of all

I am going to challenge you a little bit to think differently about your cutting.
You have used the word "can't" several times.
You "can't tell anyone" and you "can't stop"

But you can. You can stop cutting, and you can ask for help. You just need the resources and tools to help you do that.

So I encourage you to challenge yourself. Why can't you? Are you physically not able? Or just not willing? There are better ways to cope, I promise. You just need to be willing to try.

If you absolutely don't feel like you can be safe from yourself, then you need to go to an emergency room so that you can get the care you deserve.

Be kind to yourself