hey,
I'm a video editor in NY, working mostly in reality TV. To get started with editing as a career, there's a few routes. I personally didn't go to school for it, and in my opinion your time is better used learning the programs on your own and getting real world experience. It's competitive, and to give yourself the best shake get awesome at FCP and AVID. In TV (in the states) its pretty equally split between the two. This means purchasing the Student version of Avid and practicing at home, get some tutorial DVDs, do a project with Avid, or even take a class. I assume you've gotten pretty good at Final Cut by now.
So that's the obvious step. The next thing is, move. I guess to London. Because here in the US, if you want to have real options as an editor you need to live in NYC or LA. Or get EXTREMELY lucky working for one of the 3 production houses in whatever smaller city one currently lives in, or work in event videography (which is perfectly great way to earn a living, but maybe not the most exciting).
I say:
Go to London, get an internship. Get good enough to step up when you're asked to, after months of loading in footage overnight.
And good luck! I've been an editor for 10 years. I don't always work on the most exciting stuff and sometimes the hrs are really long, but I still love it. I'm making more money at this than I ever thought I would (at this stage, ro 2500-3000/wk, and there's totally room to grow!). But also, I struggled for a long time, I went years where I barely worked 3 months. So stick with it youll get there!