Who is this 'I'? Is 'I' a collection of thoughts and feelings? Does 'I' include some semblance of physical appearance? Where does this 'I' start and end? If 'I' eat an apple, is it still an apple or is it now 'I'?
I realise these are tricky questions to think about, please try not to worry. If it helps, I can tell you that I've less fear of death after taking time to think about this sort of stuff, I hope in time you'll find a sense of peace too. If you want to explore it some more, I'm here for you.
I'll try explaining the whole heaven/hell thing again. What does hell look like to you? Is it millions of former people being tortured for not living a virtuous life? If you go to hell, what part of you goes to hell? Do the former people in hell have bodies and faces? Do the former people keep their memories of their past life? Do the former people still think like the people they once were as humans?
If you want another example, say a bread roll. If you eat a bread roll, is it still a bread roll or does it become part of 'I'?