First ask yourself these questions:
Do you have any responsibilities?
Are you young enough such that you can go into something more stable if things don't "work out"?
If your answers are "no" and "yes" then go for it. You'll be better off for having done something different. It might set you back some years if you were to pursue your career like everybody else (in case it doesn't work out as planned), but when you're stuck in a cubicle looking back you will know what it's worth.
I hope you make it doing whatever you are aiming for so that you don't have to look back - and that brings up another point: don't look back if you choose to do something risky. It's do or die!!!
YAY!
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Now for the real answer to your question:
If you need to ask somebody if you should or should not, then you probably shouldn't.
Until you believe in yourself to be able to make it then don't commit. The fact that you are asking is telling me that there is some self-doubt, and this will be your biggest obstacle. When things seem darkest, your mettle must be such that you stick it out and see it to the end, no matter what the results are to be.
First overcome your self doubt and then see if you need to ask anybody your question. The choice to do one thing over another must come from within yourself, not from the advice of others.
I'd rather be brutally honest with you instead of sticking to the line above my real answer...if you had the courage to go for it, then you wouldn't be worried about "breaking the news" to your parents because there would be no question in your mind about your success. Yes, I'm being harsh, but this is NOTHING compared to what you might encounter out in the wild, or from your parents... ;) If you believe in yourself, then nothing I could say would change your mind.
I'm not advising you to be pig-headed or stubborn but rather seek a state of mind called "self-confidence". Your question is indicative of the fact that self-confidence to pursue this direction is lacking. I would rather you reflect upon this fact instead of responding because I'll only tell you in response: you don't need to justify yourself to anybody but yourself.
Read "The Unfettered Mind" by Takuan Soho. If you can understand "immovable wisdom" then you have taken the first step in a long journey towards becoming more confident with what you want to do.
Being at peace with the outcome of your action (both good and bad) is a totally separate issue!
EDIT: First step to becoming more confident: capitalize the 'I' in any sentence that refers to yourself. It speaks volumes when you capitalize other proper nouns but don't do the same for yourself!