Most Helpful Guy
Can be manipulation , can be his weak mental state. In that case its good to call anti suicidal line. You'll find number in net.
Most Helpful Girl
It means they have underlying unresolved issues that you aren't aware of. No one threatens or acts succidal just over one incident. No matter how upsetting it is. They generally have prolonged emotional pain which is deep-rooted.
He's trying to manipulate you. I'd never go back to a guy just cos he threatened suicide , and if he did follow through with it, I'd feel sad about it but not guilty. He took his own life, not me. People are solely responsible for their own actions. If he chooses to respond to you ending the relationship with succide then that's how he chooses to react and respond. That's not your responsibility