@mel123,
Hi mel
What you had experience is just another variant of panic attack. There can be actually numerous kinds of panic attack. The hyperventilation is a natural body reaction if it didn't occur then maybe you were able to do proper breathing methods that is was able to subdue the adrenaline. I know it's scary because it's new but the good news is no matter what variant it may be the solution or treatment will always be the same. Base on what you had written I'm assuming that you already have been diagnosed with panic attacks.
When this episode recurs be sure that you're prepared with the right things to do. Sit down immediately and calm down. Meditate and do some breathing exercises. You should also consider drinking herbal tea and nutritional supplements. Endoca hemp products are proven to be effective in calming down panic attacks and subduing anxiety.
If all else fails then start considering taking up anti-depressant medications.