Negative emotions (like sadness, stress, anger, etc.) causes your Serotonin production to be low; when your Serotonin level is low, you are more prone to getting Anxiety, Panic Attacks, Depression, etc.
Medication like Antidepressants (SSRI - Selective Serotonin Reuptake Inhibitor) helps to boost Serotonin level.
But there are natural ways to do it without medication. There's this strange herb called "St John's Wort" - it is said to be more effective than Prozac. No, it is not for mild depression only and ignore those sayings. In fact, it does help anxiety and panic-attacks as St John's Wort works like prozac. Other natural ways will be exercise, diet, more exposure to light, etc.
The problem is that, even if your Serotonin is balanced... you have that "learned behavior" in your mind. You need to break that initial cycle to destroy that learned behavior - Cognitive Behavior Therapy (CBT) does this. A technique that you can use without CBT will be Distraction... There are several other techniques to help cope them!
Ok, to use Distraction: Firstly, try to....
Extracted from Source.