Corporate life is not easy, but it is not as difficult as you thought. Put a full-stop to your train of thoughts; stop worrying about how other people think. If you feel that you need clarification, then clarify. Asking questions will not make you look stupid. If you did something wrong, apologize. Don't let your ego become the better of you. If you were unfairly treated, go somewhere better. The world is gigantic even if Singapore is just a tiny dot. Somewhere out there, someone will appreciate you for who you are.
Take on the perspective which makes you feel better everyday. Think positive to be positive. Words said are easier than actions done, but if you don't even think about saying it, how would you think about doing it? Right? I know I'm right *smirk*
My favorite go-to saying, 'Those who matters, matters. Those who doesn't, don't waste your time and energy on them.'