stop someone from committing suicide

I’ve been in my relationship with my boyfriend for at least a month now and we are perfect for each other but he had a rough past that involved a couple suicide attempts. I always have a compassionate heart towards people that had rough lives and I’m glad he has me but my fear is what will happen if we have to separate. He said he’d never leave and if I did would be in a worse depression then he was before I met him. He told me he’d definitely would kill himself if he lost me. I love him so much but I don’t really want to be ‘the edge’ for him if it does happen it makes me upset and cry terribly. I don’t to hear after our break-up (if it happens) that he’s in a coffin or there’s a bullet through his head because then I’ll feel guilty for not stopping it. For now I think being the decider is inevitable and I just need to deal with it but if it means keeping another out of suicide’s hands then I’ll accept it 2 weeks ago