Can someone looks and suggest what to do? Many lea...

Its nutrient burn. You have a salt buildup in your medium which is causing a nutrient lockout. Water with just water for the next couple times and you should see some improvement. When feeding you should only feed once a week and then just water the rest of the time. You never want to feed every watering. Happy Growing

Feed her more!!!

for sure the night temp is really low and affect directly to P absortion it even make the water retain less solved oxygen, the optimum range is at 23ºC try to get at least 20-21ºC.

Only 1ml per Litre of grow is probably your problem my friend I would increase the grow part of your feed abit its most probably a nitrogen deficiency nitrogen is a mobile nutrient within the plant meaning like P and K and calmag they are in constant use by the plant no matter what stage of growth your in yes they dont use as much in flower but they still use it :) if you feed her bit more when she has dried out im sure you will be fine :) Best of luck for the finish :) its defo not too late to save her even if you did nothing and kept feeding her she would still contiue to grow she would just yellow more :) its really really hard to kill a plant they are weeds after all :)