Searching for shiver

I see it better
Exponentialy getting worse
I write the good letter
but attached is the curse
envisioning great
I live in the middle
it's all just a wait
I've lost at the riddle
touched by the gods
but now they've turned
what once was prods
has left me burned
laughter can heal
but also it kills
a victim to steal
a ride for cheap thrills
clearing the mind
touching the river
when do I find
what makes me shiver?