Uni Girl - Performance and Work

I am lucky in so many ways. I am at university getting a degree in something I love - BA of Contemporary Performance, and I've been lucky enough to be involved with heaps of productions in the last two years (since graduating from high school). But there is one little problem... money. I have two casual/ part time jobs: I'm a waitress and a clown for kid's birthday's parties (my hobby job I call it :)) But in the past few weeks (and coming) I feel terrible as I've told them that I can't do a few dates... because of performing reasons. I realise that I'm taking alot of nights off because I'm performing, and frankly, I can see my bosses are not happy - and I don't blame them. I thought when I came out of school it would be easy to do heaps of theatre with my licence and new found freedom. But, I find I am a little over my head. It's hard to fit everything into spare time when that spare time is usually taken up by either work OR theatre. It's hard enough when you have one, but now I'm finding both are near impossible to do and keep a balanced lifestyle. So my question goes out to all those who did/ does a full time study/ work, one or two part time work/ study activities as well as theatre. How do you balance it?