blow a fuse — If you blow a fuse, you suddenly become very angry and are unable to stay calm.
neurasthenia — Psychiatry. (not in technical use) nervous debility and exhaustion occurring in the absence of objective causes or lesions; nervous exhaustion.
jitters — jitters, nervousness; a feeling of fright or uneasiness (usually preceded by the): Every time I have to make a speech, I get the jitters.
cold sweat — If you are in a cold sweat, you are sweating and feel cold, usually because you are very afraid or nervous.
butterflies — tremors in the stomach region due to nervousness