I cut myself again in the bathroom last night and can't tell my roommates about it.
Why did you cut yourself?
I want to die and no one can stop me
It sounds like you are going through a rough time. Self-harm isn't a solution to depression. Talk to a professional or even a web based therapy chat to get support.
I know better. I can fix myself.
That's good, because self-harm will give you scars that you can't ever fix. How about going to a therapist first, so your roommates don't have to find out? They can definitely guide you in the right way so you can never feel this pain again.