Do you have days or weeks until the event?
If weeks:
Your username suggests you may have access to plenty of good food - but, if you need reminding, you do need to start with nutrition. Increase your fruit and vegetable intake (whether weekly veg box or home grown or whatever).
Cut out alcohol completely.
Ideally arrange a course of massages; at least once a week, if not more.
Do some yoga or Pilates - whatever works best for you. It’ll improve your posture and physical resilience so you’ll sleep better, move better and wear clothes better.
You can’t force yourself to sleep, but at least ensure you arrange things so that you can get the best rest possible.
If you only have days …
Surely you can influence the conditions in the press room?
In addition to all the good advice from pp above - if possible wear an item of jewellery that will help light up your face. And clothes you feel confident and happy in.
It all sounds tremendous - I hope it goes well for you.