It's pretty hard to get full time work for 3 months, unless you lie and don't tell your employer you're going to uni in March. Getting into retail would probably be the best thing. During christmas/stocktake, I usually work a full day on weekdays during christmas holidays even if I'm only a casual. Only bad thing about that is you don't know when you're working and they'll wake you up at 7.30 am to ask you to be at work in an hour.