Ah, we've all done that at one time or another, I think
I don't know of anyone in Suffolk or Essex that stocks (or has "in stock") the D-Li90. Park Cameras in the West End of London have it, at £59. They may also do some compatible third-party batteries and chargers.
The easiest and cheapest solution is if you know someone locally with Amazon Prime membership, as they could order the necessary items for you and have them delivered tomorrow. If I was closer, I'd happily do it for you, but I'm way up North and would have to post onwards to you, which could take a couple of days.
EDIT: If you get really stuck, I could charge up a couple of my third party batteries and post them to you first thing tomorrow morning for next day delivery. That would at least give you a few hundred shots to play with