Brother is approaching suicidal and just want Perspective

Howdy M 23 here. I live with my brother rn, M20. For reference I also have depression but have never been suicidal. The worst that's gotten is deep existentialism and dissocation.

To keep it short. My brother doesn't leave the house, he doesn't eat 3 square meals, he will occasionally talk to friends but he's plainly miserable in his body. I think I'd be an idiot to not think he's constantly thinking about suicide. I've told him that his feelings are valid cause I'm tired of family trying hard for him with the basic niceties. It is inherently selfish, and honestly? I don't regret that too much from my perspective.

But the main thing I want to hear is how to help. I am not in a mental state where losing my brother to suicide would in any way keep my stable, but at the same time I'm tired of seeing him suffer daily. I at least want him to make 30 or at least our parents death or infirmity before seriously considering doing the deed, cause they wouldn't take it and become more embittered than they already are. They're well-meaning, not typically abusive but they are also very disconnected from a depressive way of life in general since they are both successful people.

I'm not even gonna pretend I can save him directly, but is there anything I can do to try and ease what will I fear is an eventual inevitability or learn to cope and show support while not trying to make him suffer more?