Work or Study?

I would disagree. While it's still important to study, however Singapore is saturated with degree holders whereby you will meet stiff competition in getting jobs and a degree nowadays doesn't guarantee you a job unlike the old days.

Work while you study. Get your work exp and establish some connections in the field which you want to work in. After two years of work and getting your degree, you will be in a better position than those who only attended full time studies.