El Supremo -
Strange to read your post as I seem to be going through a similar dilemna at the moment. I completed a degree last year in Politics and IR then went straight in to working in the London property industry (read Estate Agent...BIG MISTAKE!!!!). Luckily I have now left and have a place to do my Law conversion in September (deposit not yet paid), however I have always wanted to fly as a career. What to do as it's a tough one?!!
I really feel for you in regards to the 'if your not sure, is flying really for you?' front. There is a huge amount of negativity about flying as a career (much of it to be read on this forum) from a huge amount of people and in many respects they are right - as you are, not to simply leap in to the fray having not tried to exhaust as much as possible if this is really what you want to do. I know, I am going through the same process.
Having made one or two slightly half hearted attempts before University, one thing I do know is that when you commit, be it Law or the ATPL, you need to be commited 100%. It's not easy but you are absolutely right to question and then question again.
MM
PS. Obvious point but before you make a decision make sure you have a Class 1 Medical (Otherwise the decision will be made for you!)