despite the fact i'm horribly late to reply to this, and most of the ideas have already been said, id just like to enforce them all.
the whole driving in a carpark idea - brilliant. i never did that on my Ls, despite the fact I ended up doing about 70 hours... perhaps a little more.
after you've spent some time driving with people you're comfortable around, i'd definately recommend getting an instructor. they teach you the little things that your folks (or whoever) may not pick up on. for example: I had been driving for about a year, (well over the 50hr mark) before I even decided to get an instructor. the only reason we got an instructor was for this reason exactly - to pick up on anything little i was doing wrong...
i went with ABC, and the guy was aboslutely great. easy to get along with, to talk to, everything. after 10 minutes of driving, we pulled over and he tells me that i have everything down patt, except one thing - when i turned the wheel, my hand would go on the inside if the wheel, and if i did that in the P's test, i would fail. period.
the next 50 minutes, as well as other lessons were spent just fine tuning that and a few other nick-nacks i was doing wrong.
i never learnt to drive in a manual - ive driven one, but have never "learnt", in the true sense of the word... so my idea here may not be appropriate, but still, it's worth a shot:
if you're just uncomfortable driving, if it's possible, maybe you should do a bit of driving in an automatic, just go get a feel for the road, and interactions with drivers and signs, lights and everything. then, once you've gotten comfortable BEING on the road, switch over into a manual car, where the only real difference is the changing of gears, and in effect, breaking. those tasks ma take a bit of getting used to, but they may be easier to get used to after you're comfortable in the car. hell, you can practice them in the empty parking lot straight out if you'd really want... depends on you.
thats about it... i'll just add, that driving can be stressful. there are lots of idiots out there, who are on their full licence, and just don't obey the rules... but, driving can also be a great stress reliever. just to go for a drive would clear my head completely... i can't do that anymore considering the price of petrol, but still. driving isn't something to be afraid of... but don't be in any hurry to get your Ps either... take your time. i took a year and a half, despite the fact I could have been on them in about 6 months if i were allowed to. hell, my mate just turned 19 and only just got his Ls. dont think there's any pressure to get your licence. if your folks or whoever are pressuring you, just ask em nicely to back off a bit and let you do it in your own time...
all the best, snail. hope to hear from you when you get your licence =)
see you on the road.