So, after a conversation with Nurse-on-call (a really great service if you ever have the need to use it), the actual doctor (not so worth while, only go if you need a medical certificate) and cursing the web, it looks like most of the symptoms I have always associated with the pain are all to do with Hyperventilation Syndrome and anxiety or 'panic attack'.
a bit of a worry
a huge relief
So next time the pain comes, we'll have to see how I cope. Go on pain, I dare you! I've got you all figured out now and I not going to let you mess with me again! HA!