Mourning someone who isn’t even dead

My bf and I broke up. We’ve been together since high school. I can’t stop crying and screaming. I feel like I’m mourning his death… I’m trying to be strong for our kids but it’s literally the hardest thing I’ve ever gone through. They ask me where he is and I just break down crying. I need words of encouragement…

He’s staying with a friend right now because he said he needs space… I know he’ll be around for his kids. But I’d rather us be together instead of co parenting. I’m just not taking this break up so well. I haven’t been okay.