Hey Ryan,
I gave your tracks a listen and I think the two main areas for improvement are
1) pronunciation - a huge problem with Asians and Singaporeans in particular (including myself), there is too much weight in our words making them sound unnatural. In my opinion, it takes a tonne of practise with a professional to get anywhere with this unless you can expose yourself to a lot of native English speaking, or listen very carefully to how Caucasians sing their every word.
2) the lack of fade-off at the end of notes - meaning that you are cutting your words and notes too abruptly. you can give it a slight tailing off if the genre isn't too fast.
Hope it was constructive!
Gary.