You will be flying on a Jumbo, a nice big plane, and depending on the class (Economy, business, First) will determine how much room you have around you and how big your seat is.
There will be a tv in the back of the seat in front so you can watch movies or listen to radio channels with headphones (Virgin will provide these because they don't use a normal 3.5mm plug)
Ok the Sinus problem, yes it happens because of the change in pressure. But don't worry! There is a cure, try sucking on a sweet, most people do that and it works fine, keep swallowing too, but don't swallow the sweet!
If that doesn't work....................Pinch your nose so you can't breathe through it at all, then take a big deep breath in through your mouth and try and breath out through your nose (While it is still blocked) It will equalise the pressure instantly and no pain of deafness :)
I learnt this Scuba Diving, works on the same theory
Cabin crew are nice enough, it's their job to smile and bring you drinks etc when you want.
Toilets: Well they're not scary at all, there's a mirror, bright light, everything in a normal public toilet really, just a little more......Cosy
Enjoy the holiday
Frequent Long Haul Flyer