i only use whey and multi vits along with green tea extract and
fish oil. Creatine too ex for me 
Anyway, TS, you really need to improve your diet first. Don't worry
about the protein yet; it won't expire so fast... Diet wise, you
can change it within a day, so you should start doing from
today.
Regarding food intake, if your exercise intensity and caloric
expenditure is high enough, you will find that you will eat more
and more. Even right now, I'm eating a meal as I type... And in
your case, I believe you will need to take in a lot more carbs...
Just eat a lot a lot more, twice to thrice your current amount as I
have said... If you don't eat enough, extra protein will be broken
down as energy, and not repair your muscles after a workout, which
will be quite a waste...
4 piece of zhui kueh is damn little for lunch, and it isn't exactly
very nutritious. At least have a bowl of fish soup; that's much
better...