Excruciating (adjective)

1. Extremely painful.
2. Intensely or unendurably distressing to the mind or senses.

Origin:

Late 16th century: from latin excruciat- "tortured", from the verb excruciare, from ex- "out" + cruciare "crucify".

Examples:

1. The headache was excruciating.
2. The pain was so excruciating that he couldn't move.
3. The movie was an excruciating experience.
4. She felt an excruciating pain in her back.
5. The noise was an excruciating experience, it was so loud.