ghastinating
A portmanteau of "ghastly" and "fascinating." While the definition is self-explanatory, I'll provide an example:
I thought this up trying to recall a scene when I was immersed in nature. Sitting perfectly still near my pond for a long time, I saw a snake catch a frog. The frog continued to scream while the snake swallowed it. Even though I felt completely appalled and filled with a mad urge to somehow rescue the poor frog, I was still totally engrossed in the scene and felt, somehow, privileged to be a part of it. The experience was totally ghastinating.