Nikon D3100 upgrade lens
I don't believe your point and shoot is better though.... you may have much to gain from improving technique and other esttings before dishing out over a grand on a lens.
I don't know about his P&S, but mine is pretty good in comparison to the 18-55.
But to the OP:
Consider breaking your task up into two:
1) a better all around zoom: 18-105 is pretty good.
2) low light lens. 35/1.8 gets good marks. The difference between 1.8 and 5.6 is huge.