Unnerving (adjective)

1. Making one feel uneasy, anxious, or uncertain.
2. Causing one to lose confidence or composure.

Origin:

Late 19th century: from un- (expressing negation) + nerve.

Examples:

1. The silence was unnerving.
2. The experience was unnerving.
3. The constant attention was unnerving.
4. The sudden change in his behavior was unnerving.
5. The darkness was unnerving.