Well my studying time varied from day to day.On average I studied 7-8 hours daily.
For essay I'd recommend you to choose an essay topic on the current affairs. Every year there are at least 2 or 3 topics relating to current affairs in essay paper. Try to print out articles from different newspapers websites(nation,dawn,news and daily times), file them and arrange them by topics. Then make a note on which topics articles are being wtitten frequently_those would be important
Make an outline before writing your essay. Divide it into paragraphs and cite quotations. For quotations you can try this website
www.brainyquote.com
Brother Noor I hope that you'll get good marks InshAllah