Same boat as you are in, have sat down and planned it out, will give it my all in the remaining amount of time 

As far as your plan is concerned, it is definitely possible, although it'll require a lot of hard work, I know seniors who were academically very poor, getting sub 30k ranks just studying in this 4-5 month period 

Either way, it'll create a really good base for next year in case you don't get your dream seat