Thanks all for your replies and advice.
Wangus, I appreciate your honesty. I'm under no illusions about what it would be like to work as a pilot, and I believe I'm prepared for the hard yards.
In any case, I have a bit of cash in reserve from selling my investment property, and although it won't be easy parting with this money, it's a hell of a lot better than going in to debt. Thus, if things don't work out, I'm fortunate enough that I won't have a loan to pay off.
I'll do the PPL and see how I go, and thanks all for the "good lucks"!