No longer a gym rat

Ok so ive been killing it in the gym for the last 3 months and i was able to drop 37lb, but i start back to school in a few days and i work fulltime and go to school so today i when out got bought a treadmill.

I was doing 25mins of cardio plus my workout when i was at the gym, so i figure if i up my carido to 1hr 2twice aday ill be able to lose more weight

any advice for me on how to loss weight by doing cardio on a treadmill