I understand about the personal family situations - and it's that sort of thing that gets me down most frequently. And sometimes, even the reward of heaven isn't enough - I blame it on high IQ - apparently, it makes one more prone to "existential depression."
Someone illustrated this life very well a few weeks ago... A long piece of string tangled round the lot of us... all intertwined... our mortal life was represented by a single ribbon tied in the middle. It really puts things into perspective. We will exist far beyond what we see now... unfortunately, we just can't see very far.