Filling With Panic

This morning, I went to the dentist to have a wisdom tooth filled.

I was lying in the chair and he was working right at the back of my mouth, there was a cotton pad either side of my gum and my mouth was full up with all sorts of 'stuff' and I started to panic that I couldn't breathe, the more I thought about it, the more difficult it was to breathe and well, I just lost it and started to choke and they had to stop, I was in a blind panic and everything in the room was distant, the dentist was speaking to me and I couldn't hear him, I couldn't breathe and I was spinning around completely out of control. The dentist seemed to take it in his stride (maybe loads of other people freak out too ?) he was holding my arm and as I realised this, I came back a bit and I could hear him again, he calmed me down, telling me to breathe slowly and deeply through my nose .. I was able to do this and I started to feel calmer, I told him I had felt like I couldn't breathe. He said that while he is working at the very back of my mouth, that I should continue now to breathe slowly and deeply through my nose and that if I want him to stop I should just put my hand up, he will take as many breaks as I need. He started again .. I breathed like he said and did not need to ask him to stop again.

As I was leaving he said "Thank you for your patience" !! My patience ???

This has never happened before .. I'm supposed to be getting better at dealing with things, not loosing it worse ???

Principles ??? Spine ???