Its good to see you are pursuing your passion, but as unfortunately in a society as pragmatic as Singapore the nature of things make it extremely tough for individuals pursuing work outside of mainstream society to make an equivalent of many others in the areas more relevant to mainstream work.

In your situation at the moment its a really tough call, given your age you really need to think carefully and have the determination to see it thru.

Thinking a little out of the box, are you doing any freelance work with your artistic talents? If you could find a way to marry up your passion and mainstream work it might be a good way for you to pursue? I.e Logi designs for company, Website designing, designing marketing campaigns and stuff.

All this will not fall in your lap of course, if you are good in what you do creativity should be able to marry up the consumer needs and your talents, however you will need to go out and find consumers to actually know/trust you and build a namesake for yourself.

With regards to teaching, if you don't have the passion might want to think twice. Teaching is pretty demanding job. I know of teachers given so must stuff to do (arrange ciriculam, mark test papers, rowdy classroom, unreasonable parents, organize after school activities etc etc). I'm not interested in teaching but I already know this, so if you are even considering this path you should know alot more than I do. If you don't then better go find out.