first of all, how long is your plant flowering? Can u tell? When did she start to go white? Dude she looks healthy and dont use any fertilizers, just add some organic fertilized soil, you will find it in any grow shop. Ant thats all i think. (or u can use some chem fert with high phosphorus levels) As for the leaves, the really fucked up, dead ones, remove them. Leave the others, dont hurt them.