Fine, you sound like a decent young chap, we may have been a little harsh on you... but just wanted to open your eyes to the working world. It's a pity that your generation is so sheltered that many of your contemporaries will no doubt have this thinking and approach towards work as well.

But good on you for recognizing it and fighting on. It's easy to give up when we meet challenges, it's just human nature's fight or flee instinct, i.e. the flee part. If the work is too demanding and affecting your studies, my advice is to move into a non-sales role and prioritize your studies, as Singapore is a 'paper' country. Without paper, you can't go far in the corporate world.