My first boyfriend said the same thing in high school. He is now married and has four kids and is completely fine. Sometimes, young people don't know how to deal with something, especially if it's their first heartbreak, so they say and do all kinds of things to get your sympathy and try to get you back with them. They basically haven't developed the tools yet to handle their emotions constructively. If someone is using suicide as a ploy to get you back into their life, that's manipulative. People who really commit suicide don't do this. If anything, they usually keep quiet and hide it. We all have our hearts broken at some point, it's part of life. This is just hard for him because it's the first time but he'll have to get through it, it's part of growing up and it's not your job to help him with that. If you aren't together anymore, it isn't your responsibility and part of maturing is learning how to handle yourself on your own. Obviously, he's desperate to get you back and this is his strategy. You aren't together anymore, you can be with whoever you want and now you are in a new relationship. Of course that hurts for him, but it's a reality and the more you try to help him the more he will try to exploit this situation. I know it's hard, but move on and give him the freedom and space to grow up and do the same.