Ohh wow, yes, I can relate to this. My son breaks down a lot, sometimes its over nothing and then other times its over something really deep.
The other day I looked over at him and I could see tears welling up, so I asked him what was wrong and he burst into tears saying "I don't want you to die". I said "I'm not going to die, yet" and he said "but you will eventually" (I'm getting teary just thinking about it). Then on the other hand, this morning he was crying because his teddy dropped on the floor outside and may have gotten dirty. Sometimes I feel like saying "are you kidding me?".
I tiptoe around him more than I should, but I know that little things can set him off and his feelings get hurt really easily. He can be emotionally draining, in fact all my kids can, sometimes I need a break. I totally get where you are coming from.
My son is very concerned and even preoccupied at times with death. He says these same kinds of things to me too just out of the blue. He was saying bedtime prayers the other day, and he asked God to let he and his mommy die on the same day so we would never have to live without each other. Of course he followed it with "I guess that means I wouldn't live very long, so that's no good either." Haha. It is heartbreaking though b/c I'm not sure all kids think about those kinds of things. Maybe they do, but I sure never expected it from my little one. He's been saying things like that since he was at least 3 years old.
I know all about tiptoeing! It's exhausting!
