Charged with Shoplifting and providing false information to police

[Helpneeded]

Im freaking out right now, i was just charged today with shoplifting and out of fear i provided a false name to the police. When i realised they were going to hold me for 24 hours as they couldn't confirm my identity, i gave them my real name. The amount was around $100-150. This is my first offence, and i am 18 years old. I deeply regret what i did and i accept that i will have to pay a fine and/or do community service, however i REALLY do not want this to be on my record forever. I am a university student who wants to pursue a career in scientific research and i'll probably fall into a depression if this prevents me from being hired for a career. Is there anyway i can get this sealed off my record or expunged? I haven't hired a lawyer or anything, and probably can not afford a private one, so what are the chances of having this permanently on my record forever with a public defender?

 

[Helpneeded]

I forgot to add this was in sydney in the sate of new south wales

 

[Oneman]

I would have thought that being a university student you would have considered your predicament a little more as you were slowly plummeting into the depths of a personal disaster and telling the Police 'porky pies'.
I'm in Queensland and had quite a bit to do with 'shoppies' up here and I would assume my advice would be relevant in NSW too, but hopefully you'll get someone from NSW giving you a more certain answer based on NSW experience.
You can defend yourself if you can stand up in front of a Magistrate and tell him your story, provide a hundred excuses why you did it in the first place and then grovel and beg some more (which is all lawyers do on behalf of their clients anyway). I'm pretty sure that you can tell the Magistrate you're extremely repentant and more than willing to do some community service as penance and then beg him/her not to record a conviction as you're just young and stupid and have seen the error of your ways. Public defenders are just like everyone else in this world, there are good ones and bad ones. If you can't get up and speak for yourself, use a Legal Aid Lawyer, you might be lucky.
I'll give you a bit of advice. You can lie to your parents, your girl or boy friend or your mates, but never lie to someone who is part of 'The System', like a Police Officer, The Taxman or the Doctor in the Emergency Room, especially if you're in fear, because to tell lies you have to be cool, calm and calculating and you can't do any of that if you're frightened. I can tell you from experience that if you push a Cop, he'll usually push back harder, and usually he'll win.
If you're worried now, then that probably isn't a bad thing, as you'll think twice about breaking the law next time, but if you sit down calmly and think about your predicament and talk with someone who is a little smarter than you, then you might just find a way to save you future career. Good luck.