Man, 300 hours from now until June 2016 is already less than an hour a day… Besides, like pro_girl mentioned, you could`t have really started any earlier…
Keep in mind that 300 hours is what the CFAI recommends as a guidline, it is definetly not a requirment or guarentee of success. People study way over 300 hours and fail and study way less than 300 and pass.
For me the key was timing.. I didnt want to peak to early and get complacent and start relaxing but at the same time you can`t risk taking too long and not covering all the material.. set up a schedule where you will be peaking right when you have to take the test.. you want to be at peak performance going into June.