My boyfriend has severe depression

Hi.

To make a long story short, I have a boyfriend. Whenever we get into a little argument, he harms himself.

If he doesn’t get enough attention, he harms himself.

If he feels like I don’t care, he harms himself.

In the past he’s tried to kill him self I know multiple times. I’m scared that if I try to leave him (which I don’t want to I love him) he’d kill him self.

I feel so trapped.. and I don’t know what to do.. please help me.