Till' Death Do Us Part?

I don't get some things in life.
I like to believe each person in the world has someone they're meant to be with.However, I can only believe that up to a point.Then it becomes chaos.
People die at a young age when they're just married or dating.And then people die when they're old, but they don't usually die together.
People remarry.People divorce. I mean I can understand that it may not work out the first couple of times. But the divorce thing doesn't really match with what I'm talking about now.
What happens when you die? If you end up in Heaven..and the one you were with in the beginning and they're in Heaven too what happens? You remarried..are you still with the first person? Do you still love them?
It confuses me.
I hope I don't have to find out what it's like to die alone.. If my love leaves me alone when he dies then I won't remarry, but I really hope I don't have to find out. I don't want to know what it's like to go through life without that person I depend on.It'd be hard after depending on them for so long.
Oh, when you say Till' death do us part.. Why? You should still love them afterwards..Right? I mean I think so.I guess.
[I believe in God.So I hope you won't stop reading my blog if you don't.]