Hi Ruairidh,
Well, you could continue to be insecure and freaked out, and get into fights.
Or you might come back in a few years when you have enough training under your belt that you can actually begin to apply it, and let us know how it's going.
Funny thing happens, though; As your aikido begins to get "ki" into your bones - because aikido means "your relationship with god." - you'll find that your level of consciousness will change. And you'll stop getting into situations where there is what you're calling a "fight."
In this "mental state of mind" that you can't seem to find - there is no fight.
In this "mental state of mind" that you can't seem to find - there are no blocks.
In this "mental state of mind" that you can't seem to find - there is no opponent. And if there is a shred of an opponent left - you only have to look in the mirror to find them.
In this "mental state of mind" that you can't seem to find - you have already won.
If you want to actually learn aikido, I'd suggest getting yourself back in the dojo, and train with qualified instructors. Read as much aikido material as you can get your hands on.
http://www.kinokawa.org/aikido/founder.phtml
And, maybe just be respectful, and do to others what you want them to do to you.
You can take the blue pill, pick up a few "tricks," and get back out on the streets and try your luck.
http://en.wikipedia.org/wiki/Street_fighting
Or you can take the red pill, and really learn the art. and see how deep the rabbiit hole goes.
http://en.wikipedia.org/wiki/Redpill
Hope that helps. : )