The difference between fear and terror is one of intensity and effect. Fear is authoritative. Terror is dominant. Fear generates a response. Terror triggers panic. Fear leads to action. Terror results in paralysis.
Consider, as well, the difference between liking and loving. The verb form of like means ‘to regard with favor.’ Love means ‘to have a tender or passionate affection for.’
Language tends to be an inadequate purveyor of experiences that go beyond a racing heartbeat and clammy skin. Words can go only so far, but no further. But words can spark the imagination, which can take us well beyond the feeble limits of vowels and consonants. Writers try to shape responses to their ideas through words, but only readers can complete the task with their imaginations.
A writer can coax a reader to fear. I do not know of an incidence in which I, as a reader, have ever crossed the boundary into terror due to a writer’s words. Similarly, a writer can cajole a reader to like a character. I cannot imagine myself, or anyone else, falling in love with a character.
As beautiful as words and language are, there simply is no substitute for experience.