I can't calm down I got dental sedation soon again, has anyone got any tips?

I gotta be sedated again soon for more dental surgery I remember this happening 2 years ago an i had a severe panic attack while they was putting the sedation in and I'd took valium 2 hours prior but been told to take it 1 hour before this time and my propranolol early in the morning. I'm terrified I remember well nothing after I hugged the nurse an come round with cotton wool in my mouth my memory had been wiped. I'm agoraphobic an have severe anxiety this is why I have to be sedated. :( I'm not looking forward to this...

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I can't calm down I got dental sedation soon again, has anyone got any tips?
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