Dear God, excited or what *flails inelegantly*
All thanks are due to Starshaped at TRA, who looked at the O2 and TicketMaster websites for me yesterday and confirmed I wasn't doing things all wrong! She also gave me some excellent advice re creating a TicketMaster account ahead of time and setting up my cards on it, because you only get two minutes to confirm you want the tickets.
Still can't quite believe it; I was expecting to spend two hours desperately trying to get onto the website and then find they were all sold out.
So, I've got copies of the order confirmation all over the place, and I've written it down as well. I've got a screencap of the magic moment. The money has come up as a pending transaction on my credit card. My lovely clean, paid-up-to-date credit card. All I have to do now is wait for the actual bits of paper to arrive.
But I still won't really believe it until they actually let me in on the night.