What could possibly cause all this suffering? =(

@Katalist hi mate that leaf pic looks to me that you may have spider mites check on the underside of the leaves for tiny little mites which look like black dots if so you will need to get some pesticide specifically for the spider mite As for the leaf discoloration I reckon it is due to the stress of the pest attacks Good luck mate

The white spots look like white fly damage. But the yellowing tips looks like nutrient burn. Yours so far along I would be hesitant to use any kind of spray other then soap water as it could affect the buds. Your best option is manually removing what you can and using sticky tape to try to keep them under control until harvest.