Sometimes when we lose someone we love and care about, the easiest thing to do is get angry with God and ask why. Because we are human and imperfect, with limited knowledge, we have no way of knowing what God's plan is for us or why things like this happen. I'm sure you've heard all the Christian cliches, so I won't try to convince you that God exists, or that there's life after death. But maybe you can try not to worry so much about it for now and when the pain subsides some (and it will), ask God to reveal Himself to you and give you peace of mind that He is real and so is the afterlife. If you're sincere, and God and the afterlife are real, God will give you the peace you need to accept it. And if no such peace comes, you can go on with your life assured that you tried everything you can to believe and nothing worked. The things you speak of are spiritual, things that no one can definitively assure you of. Only God can give you that assurance.
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