What to do if you break up with a partner and they threaten suicide?

I was dating my ex-bf when we began to fight more than I could handle. I was given some advice from a friend who said, "Take a break. If you cant live w/o him then you'll know the fighting is worth it because hes the one!" So i broke up with him. That night he texted me saying that his life was nothing without me and he didnt want to live if he couldnt have me. I have had bf's before that threatened suicide, so I talked to him and ensured him that his life would be fine w/o me. He told me he was going home and I should go to sleep, seeing as it was 330 am. Then he added in that if he didnt text me back when I woke up I'd know why... He then stopped texting me back. I gave up after a while and tried to go to sleep. I figured he had gotten home and fallen asleep. Just as I was about to fall asleep, at 4 am, his dad texted me saying that (well call him Bob) they hadnt seen Bob in 2 days and asked if I had seen or talked to him recently. Not wanting to worry his family if I didnt have to, I told him that I would text our friends and let him know what I could come up with. I texted everyone I could think of to see if he was at someone's house, and I texted Bob about 100 times. Finally at about 7 am Bob answered his phone and told me that he had passed out and his phone had died while he was sleeping and thats why he hadnt gotten back to me. What do I do now? I still love him and want to be with him, but I dont know if i can be with someone who could put me through this. He acted so selfish, insecure and ridiculous that I dont know if I can go back to him. I have also done some research and it seems that if he could do this, and try to guilt me into getting back with him, he will probably do it again and it will just keep getting worse....