That is not a healthy looking plant my friend. For starters dont give it any more nutes, get some proper nutrients, if its flowering you want nutrients with a low N, and higher P and K ratios. Secondly figure out what bugs are causing your plant to.... well die.... take a look at this webpage, http://vegipm.tamu.edu/imageindex.html

It contains all the main pests cannabis can encounter and some tips on how to identify them and get rid of them. Find a growshop in the city that sells insecticides for use with cannabis plants, but you will want to do that before the plant starts to flower heavily.

Some tips for keeping bugs and pests to a minimum, grow indoors, keep a clean grow space, use new soil and keep animals away from plants. I guess the fact that you live in one of the most polluted megacities in the world doesnt help either. No disrespect intended but plants need breathable air too right! Peace