Manipulative suicide threats?

So my brother has often used his depression and threatened suicide to get his way. He’s always been really manipulative that way. But I still get worried that he actually will. I can’t just let it slide and think that he wants his way.

He’s 25 and still living with us, which wouldn’t be a big deal if he had or job, or was going to college or something! He’s a high school drop out, and is taking online community college courses but failing in all of them. I offered to help him today in his math course because I’m really good at math but he just got really mad and refused.

This really pissed my dad off that my brother wouldn’t take my offer, and my dad kind of blew up at him. My dad said no one likes liars and lazy people (basically insulting my brother). My brother stormed to his room and is ignoring the family now.

I just checked my brothers secret online account (he doesn’t know I know his password, but it’s a way to monitor his moods. Bad I know…) and my brother said he’s going to end his life tonight.

He was really happy until my dad got mad at him for being lazy, so I want to say he’s just upset. But what if he does?

My family has done everything we can to help my brother, expensive psychiatrist, expensive therapists, we’ve been supporting, etc. But my brother just doesn’t want to help himself and says he likes when people feel bad for him.

What should I do?!?! I’m really scared….