Does valium calm down overactive nerves ?

Not exactly: It is a benzodiazepine and is useful for a very brief, specific emotionally difficult event - like a tragic funeral, etc. Used too much over time, it can actually cause some serious emotional problems. Again - responsible appropriate use can help a person through a hard time - all medications need to be used only as directed. Learn ways to relax - CBT therapy, yoga, meditation, etc. do work. Best!